STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) (USD $) In Thousands	Total	Common Stock Member	Additional Paid In Capital Member	Retained Earnings Member	Accumulated Other Comprehensive Income Member	Treasury Stock Member
Beginning Balance at Dec. 31, 2011		$ 48,879	$ 143,192	$ 1,163,925	$ (65,131)	$ (85,890)
Net earnings				113,844
Other comprehensive income, net	9,623				9,623
Dividends paid				(16,392)
Stock options exercised, net		311	6,431			10,077
Restricted stock			(6,233)			6,233
Other			(414)			414
Share-based compensation			8,907			521
Repurchases of common stock						(25,705)
Ending Balance at Dec. 31, 2012	1,312,592	49,190	151,883	1,261,377	(55,508)	(94,350)
Net earnings	20,943			20,943
Other comprehensive income, net	(29,019)				(29,019)
Dividends paid				(4,212)
Stock options exercised, net		151	3,587			3,766
Other			(330)			330
Share-based compensation			2,280			390
Repurchases of common stock						0
Ending Balance at Mar. 31, 2013	$ 1,310,478	$ 49,341	$ 157,420	$ 1,278,108	$ (84,527)	$ (89,864)