Parent Company Only Condensed Financial Statements (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash Flows From Operating Activities
Net income	$ 176,055	$ 135,097	$ 52,049
Adjustments to net income:
Other, net	(11,459)	(40,379)	14,650
Net cash provided by operating activities	608,021	580,009	275,871
Cash Flows From Investing Activities
Purchase of securities available-for-sale	(5,288,118)	(4,351,981)	(3,628,275)
Cash paid for acquisition	28,066	88,795	453,719
Other, net	122,649	82,196	(2,085)
Net cash used in investing activities	(2,715,318)	(383,930)	(1,319,053)
Cash Flows From Financing Activities
Cash dividends	(42,489)	(24,012)	(48,338)
Redemption of preferred stock		(200,000)	(200,000)
Repurchase of common stock warrants		(18,500)
Issuance of common stock			119,929
Proceeds from exercise of stock options	5,089	23,764	2,236
Other, net	(28,818)	(5,450)	(5,249)
Net cash (used in) provided by financing activities	1,917,422	(574,316)	1,431,843
Net (decrease) increase in cash and cash equivalents	(189,875)	(378,237)	388,661
Cash and cash equivalents at beginning of year	434,689	812,926	424,265
Cash and cash equivalents at end of period	244,814	434,689	812,926
Parent Company
Cash Flows From Operating Activities
Net income	172,421	130,464	50,085
Adjustments to net income:
Equity in undistributed income of Bank and non-bank subsidiaries	(141,358)	(139,486)	(36,066)
Other, net	20,382	13,127	41,944
Net cash provided by operating activities	51,445	4,105	55,963
Cash Flows From Investing Activities
Purchase of securities available-for-sale	(65,019)	(352,133)	(35,821)
Sales and paydowns of securities available-for-sale	77,779	304,694	67,442
Net advances to subsidiaries		(8,265)	(369,041)
Cash paid for acquisition		(6,140)
Other, net	11,036	2,520	(3,847)
Net cash used in investing activities	23,796	(59,324)	(341,267)
Cash Flows From Financing Activities
Net (decrease) increase in other borrowings	(757)	50,000	230,796
Cash dividends	(42,489)	(24,012)	(48,338)
Redemption of preferred stock		(200,000)	(200,000)
Repurchase of common stock warrants		(18,500)
Issuance of common stock			119,929
Proceeds from exercise of stock options	5,089	23,764	2,236
Other, net	1,999	470	237
Net cash (used in) provided by financing activities	(36,158)	(168,278)	104,860
Net (decrease) increase in cash and cash equivalents	39,083	(223,497)	(180,444)
Cash and cash equivalents at beginning of year	19,588	243,085	423,529
Cash and cash equivalents at end of period	$ 58,671	$ 19,588	$ 243,085