Annual report pursuant to Section 13 and 15(d)

FAIR VALUES OF ASSETS AND LIABILITIES - Significant Unobservable Level 3 Inputs (Details)

v3.3.1.900
FAIR VALUES OF ASSETS AND LIABILITIES - Significant Unobservable Level 3 Inputs (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Available-for-sale and other securities $ 8,775,441 $ 9,384,670
Derivative Liabilities | Maximum | Consensus Pricing | Level 3    
Quantitative information about level 3 fair value measurements    
Estimated Pull through % 99.80%  
Derivative Liabilities | Minimum | Consensus Pricing | Level 3    
Quantitative information about level 3 fair value measurements    
Estimated Pull through % 11.90%  
Derivative Liabilities | Weighted Average | Consensus Pricing | Level 3    
Quantitative information about level 3 fair value measurements    
Estimated Pull through % 76.70%  
MSRs | Maximum | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Constant prepayment rate 25.70%  
Spread over forward interest rate swap rates 0.092  
MSRs | Minimum | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Constant prepayment rate 7.90%  
Spread over forward interest rate swap rates 0.033  
MSRs | Weighted Average | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Constant prepayment rate 14.70%  
Spread over forward interest rate swap rates 0.054  
Derivative Assets | Maximum | Consensus Pricing | Level 3    
Quantitative information about level 3 fair value measurements    
Net market price 20.90%  
Derivative Assets | Minimum | Consensus Pricing | Level 3    
Quantitative information about level 3 fair value measurements    
Net market price (3.20%)  
Derivative Assets | Weighted Average | Consensus Pricing | Level 3    
Quantitative information about level 3 fair value measurements    
Net market price 1.90%  
Municipal securities | Maximum | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Discount rate 7.20%  
Cumulative default 50.00%  
Loss given default 80.00%  
Municipal securities | Minimum | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Discount rate 0.30%  
Cumulative default 0.10%  
Loss given default 5.00%  
Municipal securities | Weighted Average | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Discount rate 3.10%  
Cumulative default 2.10%  
Loss given default 20.50%  
Asset-backed securities | Maximum | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Discount rate 10.90%  
Cumulative prepayment rate 100.00%  
Cumulative default 100.00%  
Loss given default 100.00%  
Cure given deferral 75.00%  
Asset-backed securities | Minimum | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Discount rate 4.60%  
Cumulative prepayment rate 0.00%  
Cumulative default 1.60%  
Loss given default 85.00%  
Cure given deferral 0.00%  
Asset-backed securities | Weighted Average | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Discount rate 6.20%  
Cumulative prepayment rate 9.60%  
Cumulative default 11.10%  
Loss given default 96.60%  
Cure given deferral 36.80%  
Automobile Loan | Maximum | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Constant prepayment rate 154.20%  
Discount rate 5.00%  
Life of pool cumulative losses 2.10%  
Automobile Loan | Minimum | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Constant prepayment rate 154.20%  
Discount rate 0.20%  
Life of pool cumulative losses 2.10%  
Automobile Loan | Weighted Average | Discounted cash flow | Level 3    
Quantitative information about level 3 fair value measurements    
Constant prepayment rate 154.20%  
Discount rate 2.30%  
Life of pool cumulative losses 2.10%  
Recurring    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
MSRs $ 17,585 22,786
Available-for-sale and other securities 8,442,655 9,053,111
Automobile loans 1,748 10,590
Recurring | Level 3    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
MSRs 17,585 22,786
Derivative assets gross 6,721 4,064
Gross amounts of recognized liabilities 665 704
Available-for-sale and other securities 2,195,888 1,530,795
Automobile loans 1,748 $ 10,590
Nonrecurring | Level 3    
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Impaired loans 62,029  
Other real estate owned $ 27,342