Consolidated Statements of Shareholders' Equity Statement - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]
Common Stock, Shares, Outstanding		46,303,000
Stockholders' Equity Attributable to Parent	$ 725,417	$ 463	$ 584,795	$ 139,085	$ 1,074
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		816,000
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures		$ 8	(8)
Stock Issued During Period, Shares, Employee Stock Purchase Plans		39,000
Stock Issued During Period, Value, Employee Stock Purchase Plan	2,049		2,049
Stock Repurchased and Retired During Period, Shares		(317,000)
Stock Repurchased and Retired During Period, Value	(15,118)	$ (3)	(15,115)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	13,134		13,134
Net income	30,782			30,782
Other Comprehensive Income (Loss), Net of Tax	(468)			0	(468)
Foreign currency translation adjustments	(513)
Pension benefit plan, net of tax	45
Common Stock, Shares, Outstanding		46,834,000
Stockholders' Equity Attributable to Parent	749,231	$ 468	581,534	166,171	1,058
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		11,000
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	1	$ 1
Stock Repurchased and Retired During Period, Shares		(4,000)
Stock Repurchased and Retired During Period, Value	(209)	$ (1)	(208)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	3,529		3,529
Net income	3,696			3,696
Other Comprehensive Income (Loss), Net of Tax	(452)				(452)
Foreign currency translation adjustments	(457)
Pension benefit plan, net of tax	5
Common Stock, Shares, Outstanding		46,841,000
Stockholders' Equity Attributable to Parent	$ 755,796	$ 468	584,855	169,867	606
Common Stock, Shares, Outstanding	46,924,238	46,924,000
Stockholders' Equity Attributable to Parent	$ 771,891	$ 469	590,163	179,968	1,291
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		439,000
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures		$ 5	(5)
Stock Issued During Period, Shares, Employee Stock Purchase Plans		51,000
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,677	$ 1	1,676
Stock Repurchased and Retired During Period, Shares		(149,000)
Stock Repurchased and Retired During Period, Value	(7,434)	$ (2)	(7,432)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	14,836		14,836
Net income	33,971			33,971
Other Comprehensive Income (Loss), Net of Tax	(2,559)				(2,559)
Foreign currency translation adjustments	(367)
Pension benefit plan, net of tax	(45)
Common Stock, Shares, Outstanding		47,249,000
Stockholders' Equity Attributable to Parent	796,076	$ 472	594,670	199,830	1,104
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		25,000
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	1	$ 1
Stock Repurchased and Retired During Period, Shares		(9,000)
Stock Repurchased and Retired During Period, Value	(501)		(501)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	5,069		5,069
Net income	14,109			14,109
Other Comprehensive Income (Loss), Net of Tax	(2,372)				(2,372)
Foreign currency translation adjustments	(210)
Pension benefit plan, net of tax	$ (15)
Common Stock, Shares, Outstanding	47,265,355	47,265,000
Stockholders' Equity Attributable to Parent	$ 812,382	$ 473	$ 599,238	$ 213,939	$ (1,268)