CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Common Stock Member	Additional Paid In Capital Member	Retained Earnings Member	Accumulated Other Comprehensive Loss Member	Treasury Stock Member
Beginning Balance at Dec. 31, 2012		$ 49,190	$ 151,883	$ 1,261,377	$ (55,508)	$ (94,350)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings				137,981
Other comprehensive income, net of tax	80,767				80,767
Dividends paid/declared				(18,377)
Stock options exercised, net of tax		0	(5,728)			34,451
Restricted stock			(2,127)			5,796
Share-based compensation			6,920			430
Other			(330)			330
Ending Balance at Dec. 31, 2013	1,552,705	49,190	150,618	1,380,981	25,259	(53,343)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	71,555			71,555
Other comprehensive income, net of tax	9,520				9,520
Dividends paid/declared				(12,536)
Stock options exercised, net of tax		0	5,131			26,719
Restricted stock			(2,051)			3,155
Share-based compensation			4,052			234
Repurchases of common stock						(23,911)
Other			(377)			377
Ending Balance at Jun. 30, 2014	$ 1,634,573	$ 49,190	$ 157,373	$ 1,440,000	$ 34,779	$ (46,769)