Subordinated Notes (Details) (USD $) In Thousands, unless otherwise specified
|
12 Months Ended |
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
$ 312,894
|
|
Subordinated Debt |
1,100,860
|
1,197,091
|
Subordinated Notes Due 2013 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
0
|
49,892
|
Debt Instrument, Interest Rate, Effective Percentage |
6.21%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2013
|
|
Subordinated Notes Due 2020 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
323,856
|
350,656
|
Debt Instrument, Interest Rate, Effective Percentage |
7.00%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2020
|
|
Junior Subordianted Debentures Due 2027 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
111,816
|
111,816
|
Debt Instrument, Interest Rate, Effective Percentage |
0.94%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2027
|
|
Junior Subordinated Debentures Due 2028 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
54,593
|
54,593
|
Debt Instrument, Interest Rate, Effective Percentage |
0.87%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2028
|
|
Junior Subordinated Debentures Due 2029 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
0
|
0
|
Junior Subordinated Debentures Due 2030 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
0
|
0
|
Junior Subordinated Debentures Due 2033 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
0
|
0
|
Junior Subordinated Debentures Due 2033 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
0
|
0
|
Junior Subordinated Debentures Due 2036 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
72,165
|
72,165
|
Debt Instrument, Interest Rate, Effective Percentage |
1.65%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2036
|
|
Junior Subordinated Debentures Due 2036 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
74,320
|
74,320
|
Debt Instrument, Interest Rate, Effective Percentage |
1.65%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2036
|
|
Junior Subordinated Debentures Due 2067 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
0
|
0
|
Subordinated Notes Due 2012 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
0
|
0
|
Subordinated Notes Due 2014 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
125,109
|
130,186
|
Debt Instrument, Interest Rate, Effective Percentage |
5.00%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2014
|
|
Subordinated Notes Due 2016 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
108,038
|
110,321
|
Debt Instrument, Interest Rate, Effective Percentage |
5.59%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2016
|
|
Subordinated Notes Due 2018 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
143,749
|
150,219
|
Debt Instrument, Interest Rate, Effective Percentage |
6.67%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2018
|
|
Subordinated Notes Due 2019 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Carrying Amount |
$ 87,214
|
$ 92,923
|
Debt Instrument, Interest Rate, Effective Percentage |
5.45%
|
|
Debt Instrument, Maturity Date |
Dec. 31,
2019
|
|