Consolidated Statement of Changes in Shareholders' Equity (USD $) In Thousands, except Share data		Common Stock [Member]		Paid-in Capital [Member]	Unearned ESOP Equity [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2008		$ 328,824	[1]	$ 13,771	$ (712)	$ 132,696	$ 0	$ 474,579
Balance (in shares) at Dec. 31, 2008	[1]	25,174,274
Net income						54,317		54,317
Cash dividends on common stock						(49,704)		(49,704)
Issuance of common stock - no par value (in shares)	[1]	4,767,306
Issuance of common stock - no par value		93,184	[1]					93,184
Stock based compensation				996				996
Other comprehensive income (net of deferred tax benefit)								0
Allocation of benefits - ESOP (in shares)	[1]	34,926
Allocation of benefits - ESOP				92	712			804
Balance at Dec. 31, 2009		422,008	[1]	14,859	0	137,309	0	574,176
Balance (in shares) at Dec. 31, 2009	[1]	29,976,506
Net income						54,857		54,857
Cash dividends on common stock						(60,707)		(60,707)
Preferred stock dividends of subsidiary, noncontrolling interests						(3)		(3)
Issuance of common stock - no par value (in shares)	[1]	20,528,945
Issuance of common stock - no par value		505,486	[1]					505,486
Stock based compensation				2,167				2,167
Other comprehensive income (net of deferred tax benefit)							166	166
Balance at Dec. 31, 2010		927,494	[1]	17,026	0	131,456	166	1,076,142
Balance (in shares) at Dec. 31, 2010	[1]	50,505,451
Net income						99,710		99,710
Cash dividends on common stock						(87,320)		(87,320)
Preferred stock dividends of subsidiary, noncontrolling interests						(54)		(54)
Issuance of common stock - no par value (in shares)	[1]	140,039
Issuance of common stock - no par value		3,659	[1]					3,659
Stock based compensation				2,765				2,765
Other comprehensive income (net of deferred tax benefit)							(541)	(541)
Balance at Dec. 31, 2011		$ 931,153	[1]	$ 19,791		$ 143,792	$ (375)	$ 1,094,361
Balance (in shares) at Dec. 31, 2011	[1]	50,645,490

[1] There were 75,000,000 shares authorized in both 2010 and 2009