Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, except Share data	Total	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Series B Preferred Stock [Member]
Balance, value at Dec. 31, 2010	$ 706,878	$ 0	$ 576,905	$ 117,692	$ 12,281
Balance (in shares) at Dec. 31, 2010		0	39,338,000
Common Stock, Dividends, Per Share, Cash Paid	$ 0.27
Net income (loss)	48,037			48,037
Other comprehensive income	12,852				12,852
Issuance of common stock - stock option and other plans, value	848		848
Issuance of common stock - stock option and other plans, shares			51,000
Issuance of common stock - restricted stock awards, net of canceled awards, value	1,635		1,635
Issuance of common stock - restricted stock awards, net of canceled awards, shares			119,000
Tax benefit deficiency associated with share-based compensation			(220)
Purchase and retirement of common stock (in shares)			2,000
Purchase and retirement of common stock, value	(32)		32
Preferred dividends				0
Cash dividends paid on common stock	(10,660)			(10,660)
Preferred Stock, Dividends, Per Share, Cash Paid	$ 0.00
Balance, value at Dec. 31, 2011	759,338	0	579,136	155,069	25,133
Balance (in shares) at Dec. 31, 2011		0	39,506,000
Common Stock, Dividends, Per Share, Cash Paid	$ 0.98
Net income (loss)	46,143			46,143
Other comprehensive income	(4,984)				(4,984)
Issuance of common stock - stock option and other plans, value	713		713
Issuance of common stock - stock option and other plans, shares			40,000
Issuance of common stock - restricted stock awards, net of canceled awards, value	1,622		1,622
Issuance of common stock - restricted stock awards, net of canceled awards, shares			140,000
Cash dividends paid on common stock	(38,824)			(38,824)
Preferred Stock, Dividends, Per Share, Cash Paid	$ 0.00
Balance, value at Dec. 31, 2012	764,008	0	581,471	162,388	20,149
Balance (in shares) at Dec. 31, 2012		0	39,686,000
Common Stock, Dividends, Per Share, Cash Paid	$ 0.41
Net income (loss)	60,016			60,016
Other comprehensive income	(32,193)				(32,193)
Issuance of common stock, net of offering costs, value	276,181		273,964			2,217
Stock Adjustment Value Deferred Compensation	517
Issuance of common stock, net of offering costs, shares			11,380,000			9,000
Issuance of common stock - stock option and other plans, value	1,243		1,243
Issuance of common stock - stock option and other plans, shares	36,037		73,000
Issuance of common stock - restricted stock awards, net of canceled awards, value	2,693		2,693
Issuance of common stock - restricted stock awards, net of canceled awards, shares			144,000
Tax benefit deficiency associated with share-based compensation	1,103		1,103
Purchase and retirement of common stock (in shares)			(18,000)
Purchase and retirement of common stock, value	(429)		(429)
Dividends, Preferred Stock, Cash	(32)
Cash dividends paid on common stock	(19,858)			(19,858)
Preferred Stock, Dividends, Per Share, Cash Paid	$ 0.31
Balance, value at Dec. 31, 2013	$ 1,053,249	$ 2,217	$ 860,562	$ 202,514	$ (12,044)
Balance (in shares) at Dec. 31, 2013		9,000	51,265,000