|
Held-to-Maturity Securities (Details) (USD $)
In Thousands, unless otherwise specified
|
Mar. 31, 2014
|
Dec. 31, 2013
|
| Contractual maturities of held-to-maturity securities |
|
|
| Held-to-maturity securities, Total |
$ 3,734,723
|
$ 3,836,667
|
| Held-to-maturity Securities, Fair Value |
3,701,496
|
3,760,898
|
| Amortized cost, gross unrealized gains and losses, and fair value by investment category |
|
|
| Held-to-maturity securities, Total |
3,734,723
|
3,836,667
|
| Held-to-maturity Securities, Gross Gain |
(14,522)
|
(6,349)
|
| Held-to-maturity Securities, Gross Losses |
47,749
|
82,118
|
| Held-to-maturity securities, fair value |
3,701,496
|
3,760,898
|
| Continuous Unrealized Loss Position |
|
|
| Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value |
2,611,481
|
3,001,774
|
| Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value |
(46,069)
|
(79,766)
|
| Total Temporarily Impaired Securities, Over Twelve Months, Fair Value |
23,222
|
22,548
|
| Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months |
(1,680)
|
(2,352)
|
| Total Temporarily Impaired Securities, Fair Value |
2,634,703
|
3,024,322
|
| Total Temporarily Impaired Securities, Unrealized Losses |
(47,749)
|
(82,118)
|
|
Federal agencies - mortgage backed securities [Member]
|
|
|
| Contractual maturities of held-to-maturity securities |
|
|
| Held-to-maturity Securities, Under 1 year |
0
|
0
|
| Held-to-maturity Securities, 1-5 years |
0
|
0
|
| Held-to-maturity Securities, 6-10 years |
24,901
|
24,901
|
| Held-to-maturity Securities, Over 10 years |
3,478,163
|
3,574,156
|
| Held-to-maturity securities, Total |
3,503,064
|
3,599,057
|
| Fair Value, Under 1 year |
0
|
0
|
| Fair Value, 1-5 years |
0
|
0
|
| Fair Value, 6-10 years |
23,222
|
22,549
|
| Fair Value, Over 10 years |
3,450,923
|
3,506,018
|
| Held-to-maturity Securities, Fair Value |
3,474,145
|
3,528,567
|
| Amortized cost, gross unrealized gains and losses, and fair value by investment category |
|
|
| Held-to-maturity securities, Total |
3,503,064
|
3,599,057
|
| Held-to-maturity Securities, Gross Gain |
(13,868)
|
(5,573)
|
| Held-to-maturity Securities, Gross Losses |
42,787
|
76,063
|
| Held-to-maturity securities, fair value |
3,474,145
|
3,528,567
|
| Continuous Unrealized Loss Position |
|
|
| Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value |
2,442,257
|
2,849,198
|
| Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value |
(41,107)
|
(73,711)
|
| Total Temporarily Impaired Securities, Over Twelve Months, Fair Value |
23,222
|
22,548
|
| Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months |
(1,680)
|
(2,352)
|
| Total Temporarily Impaired Securities, Fair Value |
2,465,479
|
2,871,746
|
| Total Temporarily Impaired Securities, Unrealized Losses |
(42,787)
|
(76,063)
|
|
Other Federal Agencies [Member]
|
|
|
| Contractual maturities of held-to-maturity securities |
|
|
| Held-to-maturity Securities, Under 1 year |
0
|
0
|
| Held-to-maturity Securities, 1-5 years |
0
|
0
|
| Held-to-maturity Securities, 6-10 years |
57,431
|
38,588
|
| Held-to-maturity Securities, Over 10 years |
165,424
|
189,999
|
| Held-to-maturity securities, Total |
222,855
|
228,587
|
| Fair Value, Under 1 year |
0
|
0
|
| Fair Value, 1-5 years |
0
|
0
|
| Fair Value, 6-10 years |
57,652
|
39,075
|
| Fair Value, Over 10 years |
161,433
|
185,097
|
| Held-to-maturity Securities, Fair Value |
219,085
|
224,172
|
| Amortized cost, gross unrealized gains and losses, and fair value by investment category |
|
|
| Held-to-maturity securities, Total |
222,855
|
228,587
|
| Held-to-maturity Securities, Gross Gain |
(654)
|
(776)
|
| Held-to-maturity Securities, Gross Losses |
(4,424)
|
(5,191)
|
| Held-to-maturity securities, fair value |
219,085
|
224,172
|
| Continuous Unrealized Loss Position |
|
|
| Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value |
160,958
|
144,417
|
| Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value |
(4,424)
|
(5,191)
|
| Total Temporarily Impaired Securities, Over Twelve Months, Fair Value |
0
|
0
|
| Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months |
0
|
0
|
| Total Temporarily Impaired Securities, Fair Value |
160,958
|
144,417
|
| Total Temporarily Impaired Securities, Unrealized Losses |
(4,424)
|
(5,191)
|
|
Municipal securities [Member]
|
|
|
| Contractual maturities of held-to-maturity securities |
|
|
| Held-to-maturity Securities, Under 1 year |
0
|
0
|
| Held-to-maturity Securities, 1-5 years |
0
|
0
|
| Held-to-maturity Securities, 6-10 years |
0
|
0
|
| Held-to-maturity Securities, Over 10 years |
8,804
|
9,023
|
| Held-to-maturity securities, Total |
8,804
|
9,023
|
| Fair Value, Under 1 year |
0
|
0
|
| Fair Value, 1-5 years |
0
|
0
|
| Fair Value, 6-10 years |
0
|
0
|
| Fair Value, Over 10 years |
8,266
|
8,159
|
| Held-to-maturity Securities, Fair Value |
8,266
|
8,159
|
| Amortized cost, gross unrealized gains and losses, and fair value by investment category |
|
|
| Held-to-maturity securities, Total |
8,804
|
9,023
|
| Held-to-maturity Securities, Gross Gain |
0
|
0
|
| Held-to-maturity Securities, Gross Losses |
(538)
|
(864)
|
| Held-to-maturity securities, fair value |
8,266
|
8,159
|
| Continuous Unrealized Loss Position |
|
|
| Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value |
8,266
|
8,159
|
| Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value |
(538)
|
(864)
|
| Total Temporarily Impaired Securities, Over Twelve Months, Fair Value |
0
|
0
|
| Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months |
0
|
0
|
| Total Temporarily Impaired Securities, Fair Value |
8,266
|
8,159
|
| Total Temporarily Impaired Securities, Unrealized Losses |
(538)
|
(864)
|
|
Total U.S. Government backed agencies [Member]
|
|
|
| Contractual maturities of held-to-maturity securities |
|
|
| Held-to-maturity securities, Total |
3,725,919
|
3,827,644
|
| Held-to-maturity Securities, Fair Value |
3,693,230
|
3,752,739
|
| Amortized cost, gross unrealized gains and losses, and fair value by investment category |
|
|
| Held-to-maturity securities, Total |
3,725,919
|
3,827,644
|
| Held-to-maturity Securities, Gross Gain |
(14,522)
|
(6,349)
|
| Held-to-maturity Securities, Gross Losses |
47,211
|
81,254
|
| Held-to-maturity securities, fair value |
3,693,230
|
3,752,739
|
| Continuous Unrealized Loss Position |
|
|
| Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value |
2,603,215
|
2,993,615
|
| Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value |
(45,531)
|
(78,902)
|
| Total Temporarily Impaired Securities, Over Twelve Months, Fair Value |
23,222
|
22,548
|
| Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months |
(1,680)
|
(2,352)
|
| Total Temporarily Impaired Securities, Fair Value |
2,626,437
|
3,016,163
|
| Total Temporarily Impaired Securities, Unrealized Losses |
$ (47,211)
|
$ (81,254)
|