CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY (USD $) In Thousands	Total	Regular Dividend	Special Dividend	Common Stock	Common Stock Special Dividend	Additional Paid-in Capital	Additional Paid-in Capital Special Dividend	Retained Earnings	Retained Earnings Regular Dividend	Retained Earnings Special Dividend
Balance at Dec. 31, 2010	$ 1,470,871			$ 1,098		$ 1,354,691		$ 115,082
Balance (in shares) at Dec. 31, 2010				109,754
Net income	162,510							162,510
Issuance of common stock (in shares)				3
Issuance of common stock	51					51
Retirement of common stock (in shares)				(10,661)
Retirement of common stock	(239,725)			(107)		(239,618)
Restricted stock compensation, net of forfeitures (in shares)				(22)
Restricted stock compensation, net of forfeitures	6,123					6,123
Stock option compensation expense, net of forfeitures	4,210					4,210
Income tax benefit of equity compensation	1,845					1,845
Restricted stock grants (in shares)				186
Restricted stock grants				2		(2)
Stock options exercised (in shares)				268
Stock options exercised	2,137			2		2,135
Balance at Dec. 31, 2011	1,408,022			995		1,129,435		277,592
Balance (in shares) at Dec. 31, 2011				99,528
Net income	156,761							156,761
Issuance of common stock (in shares)				1
Issuance of common stock	29					29
Retirement of common stock (in shares)				(110)
Retirement of common stock	(2,808)			(1)		(2,807)
Dividend on common stock		(60,222)							(60,222)
Restricted stock compensation, net of forfeitures (in shares)				(13)
Restricted stock compensation, net of forfeitures	7,635					7,635
Stock option compensation expense, net of forfeitures	4,661					4,661
Income tax benefit of equity compensation	2,609					2,609
Restricted stock grants (in shares)				333
Restricted stock grants				3		(3)
Stock options exercised (in shares)				366
Stock options exercised	4,933			4		4,929
Balance at Dec. 31, 2012	1,521,620			1,001		1,146,488		374,131
Balance (in shares) at Dec. 31, 2012				100,105
Net income	300,835							300,835
Issuance of common stock (in shares)				20
Issuance of common stock	27					27
Retirement of common stock (in shares)				(180)
Retirement of common stock	(6,693)			(2)		(6,691)
Dividend on common stock, (in shares)					13,878
Dividend on common stock		(221,196)	(135,546)		139		542,541		(221,196)	(678,226)
Restricted stock compensation, net of forfeitures (in shares)				(30)
Restricted stock compensation, net of forfeitures	9,822					9,381		441
Stock option compensation expense, net of forfeitures	3,116					3,116
Income tax benefit of equity compensation	351					351
Restricted stock grants (in shares)				300
Restricted stock grants				3		(3)
Stock options exercised (in shares)				1,830
Stock options exercised	30,171			18		30,153
Balance at Dec. 31, 2013	$ 1,502,507			$ 1,159		$ 1,725,363		$ (224,015)
Balance (in shares) at Dec. 31, 2013				115,923