CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock Member	Additional Paid In Capital Member	Retained Earnings Member	Accumulated Other Comprehensive Income (Loss) Member	Treasury Stock Member
Beginning Balance at Dec. 31, 2014		$ 49,190	$ 158,043	$ 1,469,306	$ (128,411)	$ (69,695)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive loss, net of tax	$ (97,517)
Ending Balance at Dec. 31, 2015	1,255,423	49,190	144,923	1,590,645	(225,928)	(303,407)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	32,819			32,819
Other comprehensive loss, net of tax	18,717				18,717
Dividends paid/declared				(5,805)
Restricted stock			(10,918)			14,447
Stock options exercised, net of tax			(2,757)			11,666
Other			(732)			735
Share-based compensation			2,356			367
Repurchases of common stock						(29,608)
Ending Balance at Mar. 31, 2016	$ 1,286,707	$ 49,187	$ 132,872	$ 1,617,659	$ (207,211)	$ (305,800)