CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2008	$ 353,479	$ 0	$ 87	$ 607,143	$ (17,715)	$ (236,036)
Balance (in shares) at Dec. 31, 2008		0	86,743,612
Increase (Decrease) in Stockholders' Equity
Non-cash, stock-based compensation	9,241	0	0	9,241	0	0
Shares issued in connection with employee stock programs	2,914	0	0	2,914	0	0
Shares issued in connection with employee stock programs (in shares)		0	733,515
Repurchase and retirement of common stock	(35,148)	0	(3)	(35,145)	0	0
Repurchase and retirement of common stock (in shares)		0	(3,599,431)
Tax benefit (shortfall) from employee stock transactions	(471)	0	0	(471)	0	0
Net income	68,616	0	0	0	0	68,616
Other comprehensive income (loss)	7,858	0	0	0	7,858	0
Balance at Dec. 31, 2009	406,489	0	84	583,682	(9,857)	(167,420)
Balance (in shares) at Dec. 31, 2009		0	83,877,696
Increase (Decrease) in Stockholders' Equity
Non-cash, stock-based compensation	7,944	0	0	7,944	0	0
Shares issued in connection with employee stock programs	4,203	0	1	4,202	0	0
Shares issued in connection with employee stock programs (in shares)		0	1,056,426
Repurchase and retirement of common stock	(38,556)	0	(4)	(38,552)	0	0
Repurchase and retirement of common stock (in shares)		0	(3,959,977)
Tax benefit (shortfall) from employee stock transactions	(1,417)	0	0	(1,417)	0	0
Net income	90,510	0	0	0	0	90,510
Other comprehensive income (loss)	3,468	0	0	0	3,468	0
Balance at Dec. 31, 2010	472,641	0	81	555,859	(6,389)	(76,910)
Balance (in shares) at Dec. 31, 2010		0	80,974,145
Increase (Decrease) in Stockholders' Equity
Non-cash, stock-based compensation	14,022	0	0	14,022	0	0
Shares issued in connection with employee stock programs	6,945	0	1	6,944	0	0
Shares issued in connection with employee stock programs (in shares)		0	1,388,101
Issuance of shares in business combinations	109,359	0	8	109,351	0	0
Issuance of shares in business combinations (in shares)		0	7,481,387
Assumed options from business combinations	6,944	0	0	6,944	0	0
Repurchase and retirement of common stock	(145,035)	0	(10)	(141,648)	0	(3,377)
Repurchase and retirement of common stock (in shares)		0	(9,704,140)
Tax benefit (shortfall) from employee stock transactions	1,136	0	0	1,136	0	0
Net income	101,130	0	0	0	0	101,130
Other comprehensive income (loss)	(3,749)	0	0	0	(3,749)	0
Balance at Dec. 31, 2011	$ 563,393	$ 0	$ 80	$ 552,608	$ (10,138)	$ 20,843
Balance (in shares) at Dec. 31, 2011		0	80,139,493