Annual report pursuant to Section 13 and 15(d)

Quarterly Results of Operations (Unaudited) (Details)

v2.4.1.9
Quarterly Results of Operations (Unaudited) (Details) (USD $)
 3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Selected Quarterly Financial Information [Abstract]                      
Interest income $ 507,625,000us-gaap_InterestAndDividendIncomeOperating $ 501,060,000us-gaap_InterestAndDividendIncomeOperating $ 495,322,000us-gaap_InterestAndDividendIncomeOperating $ 472,455,000us-gaap_InterestAndDividendIncomeOperating $ 469,824,000us-gaap_InterestAndDividendIncomeOperating $ 462,912,000us-gaap_InterestAndDividendIncomeOperating $ 462,582,000us-gaap_InterestAndDividendIncomeOperating $ 465,319,000us-gaap_InterestAndDividendIncomeOperating $ 1,976,462,000us-gaap_InterestAndDividendIncomeOperating $ 1,860,637,000us-gaap_InterestAndDividendIncomeOperating $ 1,930,263,000us-gaap_InterestAndDividendIncomeOperating
Interest Expense 34,373,000us-gaap_InterestExpense 34,725,000us-gaap_InterestExpense 35,274,000us-gaap_InterestExpense 34,949,000us-gaap_InterestExpense 39,175,000us-gaap_InterestExpense 38,060,000us-gaap_InterestExpense 37,645,000us-gaap_InterestExpense 41,149,000us-gaap_InterestExpense 139,321,000us-gaap_InterestExpense 156,029,000us-gaap_InterestExpense 219,739,000us-gaap_InterestExpense
Net interest income 473,252,000us-gaap_InterestIncomeExpenseNet 466,335,000us-gaap_InterestIncomeExpenseNet 460,048,000us-gaap_InterestIncomeExpenseNet 437,506,000us-gaap_InterestIncomeExpenseNet 430,649,000us-gaap_InterestIncomeExpenseNet 424,852,000us-gaap_InterestIncomeExpenseNet 424,937,000us-gaap_InterestIncomeExpenseNet 424,170,000us-gaap_InterestIncomeExpenseNet 1,837,141,000us-gaap_InterestIncomeExpenseNet 1,704,608,000us-gaap_InterestIncomeExpenseNet 1,710,524,000us-gaap_InterestIncomeExpenseNet
Provision for credit losses 2,494,000us-gaap_ProvisionForLoanAndLeaseLosses 24,480,000us-gaap_ProvisionForLoanAndLeaseLosses 29,385,000us-gaap_ProvisionForLoanAndLeaseLosses 24,630,000us-gaap_ProvisionForLoanAndLeaseLosses 24,331,000us-gaap_ProvisionForLoanAndLeaseLosses 11,400,000us-gaap_ProvisionForLoanAndLeaseLosses 24,722,000us-gaap_ProvisionForLoanAndLeaseLosses 29,592,000us-gaap_ProvisionForLoanAndLeaseLosses 80,989,000us-gaap_ProvisionForLoanAndLeaseLosses 90,045,000us-gaap_ProvisionForLoanAndLeaseLosses 147,388,000us-gaap_ProvisionForLoanAndLeaseLosses
Noninterest Income 233,278,000us-gaap_NoninterestIncome 247,349,000us-gaap_NoninterestIncome 250,067,000us-gaap_NoninterestIncome 248,485,000us-gaap_NoninterestIncome 249,892,000us-gaap_NoninterestIncome 253,767,000us-gaap_NoninterestIncome 251,919,000us-gaap_NoninterestIncome 256,618,000us-gaap_NoninterestIncome 979,179,000us-gaap_NoninterestIncome 1,012,196,000us-gaap_NoninterestIncome 1,106,321,000us-gaap_NoninterestIncome
Noninterest Expense 483,271,000us-gaap_NoninterestExpense 480,318,000us-gaap_NoninterestExpense 458,636,000us-gaap_NoninterestExpense 460,121,000us-gaap_NoninterestExpense 446,009,000us-gaap_NoninterestExpense 423,336,000us-gaap_NoninterestExpense 445,865,000us-gaap_NoninterestExpense 442,793,000us-gaap_NoninterestExpense 1,882,346,000us-gaap_NoninterestExpense 1,758,003,000us-gaap_NoninterestExpense 1,835,876,000us-gaap_NoninterestExpense
Income before income taxes 220,765,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 208,886,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 222,094,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 201,240,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 210,201,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 243,883,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 206,269,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 208,403,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 852,985,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 868,756,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 833,581,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Provision for income taxes 57,151,000us-gaap_IncomeTaxExpenseBenefit 53,870,000us-gaap_IncomeTaxExpenseBenefit 57,475,000us-gaap_IncomeTaxExpenseBenefit 52,097,000us-gaap_IncomeTaxExpenseBenefit 52,029,000us-gaap_IncomeTaxExpenseBenefit 65,047,000us-gaap_IncomeTaxExpenseBenefit 55,269,000us-gaap_IncomeTaxExpenseBenefit 55,129,000us-gaap_IncomeTaxExpenseBenefit 220,593,000us-gaap_IncomeTaxExpenseBenefit 227,474,000us-gaap_IncomeTaxExpenseBenefit 202,291,000us-gaap_IncomeTaxExpenseBenefit
Net income 163,614,000us-gaap_NetIncomeLoss 155,016,000us-gaap_NetIncomeLoss 164,619,000us-gaap_NetIncomeLoss 149,143,000us-gaap_NetIncomeLoss 158,172,000us-gaap_NetIncomeLoss 178,836,000us-gaap_NetIncomeLoss 151,000,000us-gaap_NetIncomeLoss 153,274,000us-gaap_NetIncomeLoss 632,392,000us-gaap_NetIncomeLoss 641,282,000us-gaap_NetIncomeLoss 631,290,000us-gaap_NetIncomeLoss
Dividends on preferred shares 7,963,000us-gaap_DividendsPreferredStock 7,964,000us-gaap_DividendsPreferredStock 7,963,000us-gaap_DividendsPreferredStock 7,964,000us-gaap_DividendsPreferredStock 7,965,000us-gaap_DividendsPreferredStock 7,967,000us-gaap_DividendsPreferredStock 7,967,000us-gaap_DividendsPreferredStock 7,970,000us-gaap_DividendsPreferredStock 31,854,000us-gaap_DividendsPreferredStock 31,869,000us-gaap_DividendsPreferredStock 31,989,000us-gaap_DividendsPreferredStock
Net income applicable to common shareholders $ 155,651,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 147,052,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 156,656,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 141,179,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 150,207,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 170,869,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 143,033,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 145,304,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 600,538,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 609,413,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 599,301,000us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Earnings Per Share, Basic $ 0.19us-gaap_EarningsPerShareBasic $ 0.18us-gaap_EarningsPerShareBasic $ 0.19us-gaap_EarningsPerShareBasic $ 0.17us-gaap_EarningsPerShareBasic $ 0.18us-gaap_EarningsPerShareBasic $ 0.21us-gaap_EarningsPerShareBasic $ 0.17us-gaap_EarningsPerShareBasic $ 0.17us-gaap_EarningsPerShareBasic $ 0.73us-gaap_EarningsPerShareBasic $ 0.73us-gaap_EarningsPerShareBasic $ 0.7us-gaap_EarningsPerShareBasic
Earnings Per Share, Diluted $ 0.19us-gaap_EarningsPerShareDiluted $ 0.18us-gaap_EarningsPerShareDiluted $ 0.19us-gaap_EarningsPerShareDiluted $ 0.17us-gaap_EarningsPerShareDiluted $ 0.18us-gaap_EarningsPerShareDiluted $ 0.2us-gaap_EarningsPerShareDiluted $ 0.17us-gaap_EarningsPerShareDiluted $ 0.17us-gaap_EarningsPerShareDiluted $ 0.72us-gaap_EarningsPerShareDiluted $ 0.72us-gaap_EarningsPerShareDiluted $ 0.69us-gaap_EarningsPerShareDiluted