Condensed Consolidated Statements of Stockholders' Equity Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares, outstanding		109,910
Total stockholders' equity	$ 286,517	$ 1,099	$ 838,436	$ 805,924	$ (1,347,677)	$ (11,265)
ASU adoption adjustment	(1,976)			(1,976)
Net earnings	7,323			7,323
Total other comprehensive income (loss)	521					521
Exercise of stock options, shares		284
Exercise of stock options	2,892	$ 3	2,889
Vesting of restricted share units, shares		218
Vesting of restricted share units	0	$ 2	(2)
Tax effect of stock awards vested and options exercised	(1,734)		(1,734)
Stock-based compensation	709		709
Net earnings	101,778			101,778
Total other comprehensive income (loss)	304
Common stock, shares, outstanding		110,412
Total stockholders' equity	294,252	$ 1,104	840,298	811,271	(1,347,677)	(10,744)
Net earnings	94,455			94,455
Total other comprehensive income (loss)	(217)
Exercise of stock options, shares		101
Exercise of stock options	1,418	$ 1	1,417
Vesting of restricted share units, shares		49
Vesting of restricted share units	0
Stock-based compensation	1,982		1,982
Common stock, shares, outstanding		110,562
Total stockholders' equity	391,890	$ 1,105	843,697	905,726	(1,347,677)	(10,961)
Common stock, shares, outstanding		111,166
Total stockholders' equity	458,963	$ 1,110	869,617	947,875	(1,348,969)	(10,670)
ASU adoption adjustment	(769)			(769)
Net earnings	49,292			49,292
Total other comprehensive income (loss)	(3,906)					(3,906)
Purchase of treasury stock	(26,525)	$ (14)			(26,511)
Exercise of stock options, shares		69
Exercise of stock options	1,195	$ 1	1,194
Vesting of restricted share units, shares		434
Vesting of restricted share units	0	$ 4	(4)
Tax effect of stock awards vested and options exercised	(5,270)		(5,270)
Stock-based compensation	3,043		3,043
Net earnings	87,785			87,785
Total other comprehensive income (loss)	(3,889)
Purchase of treasury stock	(26,500)
Common stock, shares, outstanding		111,669
Total stockholders' equity	476,023	$ 1,101	868,580	996,398	(1,375,480)	(14,576)
Net earnings	38,493			38,493
Total other comprehensive income (loss)	17
Exercise of stock options, shares		42
Exercise of stock options	486	$ 0	486
Stock-based compensation	2,849		2,849
Dividends declared	(31,292)			(31,292)
Common stock, shares, outstanding		111,711
Total stockholders' equity	$ 486,576	$ 1,101	$ 871,915	$ 1,003,599	$ (1,375,480)	$ (14,559)