Consolidated Statements Of Stockholders' Equity (USD $) In Thousands	Common Stock [Member]		Additional Paid In Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income [Member]	Total
Balance, Value at Dec. 31, 2012	$ 60		$ 460,237	$ (240)	$ 16,410	$ 3,866	$ 480,333
Balance, Shares at Dec. 31, 2012	59,855			355			89,783
Tax benefit of stock options exercised		[1]	4,229				4,229
Issuance (repurchase) of restricted stock, net, Value		[1]	306	(4)			302
Issuance (repurchase) of restricted stock, net, Shares	323			184
Issuance of stock for 5.50% senior convertible notes, Value	2		43,088				43,090
Issuance of stock for 5.50% senior convertible notes, Shares	2,173						2,979
Common stock split, Value	31		(177)		(31)		(177)
Common stock split, Shares	30,867
Stock-based compensation expense, Value			2,221				2,221
Net income					5,883		5,883
Gain on pension plan - unrealized						29	29
Foreign currency translation adjustments						(3,261)	(3,261)
Balance, Value at Mar. 31, 2013	$ 93		$ 509,904	$ (244)	$ 22,262	$ 634	$ 532,649
Balance, Shares at Mar. 31, 2013	93,218			539			93,218

[1] Amounts not shown due to rounding.