Parent Company Financial Information (Condensed Statements of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Activities
Net Income (Loss)	$ 48,037	$ 30,784	$ (3,968)
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	1,635	1,424	1,038
Net cash provided by operating activities	86,424	124,136	37,257
Investing Activities
Proceeds from termination of trust subsidiaries	774	0	0
Net cash provided by investing activities	(23,270)	278,465	69,327
Financing Activities
Cash dividends paid	(10,660)	(1,461)	(1,374)
Repayment of long-term subordinated debt	(25,774)	0	0
Proceeds from issuance of common stock	0	229,129	113,537
Purchase and retirement of common stock	(32)	0	0
Proceeds from exercise of stock options	848	923	939
Excess tax benefit from stock-based compensation	98	25	0
Net cash provided by financing activities	(282,995)	(193,545)	109,760
Increase (decrease) in cash and cash equivalents	(219,841)	209,056	216,344
Cash and cash equivalents at beginning of period	514,130	305,074	88,730
Cash and cash equivalents at end of period	294,289	514,130	305,074
Parent [Member]
Operating Activities
Net Income (Loss)	48,037	30,784	(3,968)
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed earnings of subsidiaries	(49,180)	(30,847)	3,067
Stock-based compensation expense	1,635	1,424	1,038
Net changes in other assets and liabilities	315	(769)	1,783
Net cash provided by operating activities	807	592	1,920
Investing Activities
Proceeds from termination of trust subsidiaries	774	0	0
Net cash provided by investing activities	774	0	0
Financing Activities
Net decrease in short-term borrowings	0	0	(100)
Cash dividends paid	(10,660)	(4,302)	(5,155)
Repayment of long-term subordinated debt	(25,774)
Proceeds from issuance of common stock	0	229,129	113,537
Purchase and retirement of common stock	(32)	0	0
Proceeds from exercise of stock options	848	948	939
Downstream stock offering proceeds to the Bank	(50,000)	(70,000)	(105,000)
Excess tax benefit from stock-based compensation	98	0	0
Purchase and retirement of preferred stock	0	(80,200)	0
Net cash provided by financing activities	(85,520)	75,575	4,221
Increase (decrease) in cash and cash equivalents	(83,939)	76,167	6,141
Cash and cash equivalents at beginning of period	159,173	83,006	76,865
Cash and cash equivalents at end of period	$ 75,234	$ 159,173	$ 83,006

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).