Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2010	$ 302,697	$ 240	$ 113,412	$ 188,894	$ 151
Balance, Shares at Dec. 31, 2010		24,011
Net income (loss)	60,958			60,958
Other comprehensive gain/loss, net of tax:
Unrealized gain/loss on derivative instruments	(2,119)				(2,119)
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes	(2,400)	5	(2,405)
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes, Shares		509
Stock-based compensation	7,709		7,709
Tax benefit related to stock-based compensation	4,690		4,690
Balance at Dec. 31, 2011	371,535	245	123,406	249,852	(1,968)
Balance, Shares at Dec. 31, 2011		24,520
Net income (loss)	69,477			69,477
Other comprehensive gain/loss, net of tax:
Unrealized gain/loss on derivative instruments	194				194
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes	(1,122)	5	(1,127)
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes, Shares		534
Repurchase of common stock	(49,270)	(18)	(49,252)
Repurchase of common stock, Shares		(1,863)
Stock-based compensation	8,794		8,794
Tax benefit related to stock-based compensation	3,926		3,926
Issuance of convertible notes, net	13,923		13,923
Purchase of convertible hedge and sale of warrants, net	(11,641)		(11,641)
Balance at Dec. 31, 2012	405,816	232	88,029	319,329	(1,774)
Balance, Shares at Dec. 31, 2012		23,191
Net income (loss)	73,740			75,299		(392)
Other comprehensive gain/loss, net of tax:
Unrealized gain/loss on derivative instruments	(817)				(817)
Unrealized gain on foreign currency translation (excluding $1,047 attributable to redeemable noncontrolling interests)	8,137				7,786	351
Initial noncontrolling interests related to business combinations	4,051					4,051
Change in fair value of redeemable noncontrolling interests	(1,167)		(1,167)
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes	(4,967)	6	(4,973)
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes, Shares		618
Repurchase of common stock	(729)		(729)
Repurchase of common stock, Shares		(24)
Issuance of common stock	62,352	17	62,335
Issuance of common stock, Shares		1,672
Stock-based compensation	12,649		12,649
Tax benefit related to stock-based compensation	5,420		5,420
Issuance of convertible notes, net	31,024		31,024
Purchase of convertible hedge and sale of warrants, net	(20,769)		(20,769)
Balance at Dec. 31, 2013	$ 571,897	$ 255	$ 171,819	$ 394,628	$ 5,195	$ 4,010
Balance, Shares at Dec. 31, 2013		25,457