Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Allowance for credit losses	$ 153,037	$ 137,680
Federal and state carryforwards	143	665
Accrued expenses	97,269	79,416
Non-accrual interest income	23,201	20,912
Unrealized losses on securities available-for-sale	11,116
Share-based compensation	30,371	28,993
Basis difference in investments	420	12,952
Other	2,410	3,306
Total gross deferred tax assets	317,967	283,924
Deferred tax liabilities:
Core deposit and other intangibles	9,261	11,353
State income taxes	7,855	7,763
Depreciation	3,460	6,371
Basis difference in OREO and loans	5,016	890
Deferred loan origination costs	10,686	8,483
Prepaid expenses	3,863	3,784
Unrealized gains on securities available-for-sale		62,225
Leasing activities	48,709	43,176
Basis difference in FHLB stock	9,179	13,331
Other	1,948	2,087
Total gross deferred tax liabilities	99,977	159,463
Net deferred tax assets	$ 217,990	$ 124,461