CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Balance at Dec. 31, 2012	$ 990,748	$ 65	$ 940,969	$ (59)	$ 49,773
Balance (in shares) at Dec. 31, 2012		64,713,695
Changes in Stockholders' Equity
Comprehensive loss	(12,464)			101	(12,565)
Sale of warrants	121,675		121,675
Purchase of convertible bond hedge, net of tax	(113,379)		(113,379)
Equity component of convertible debt extinguishment, net of tax	(277,491)		(277,491)
Issuance of common stock upon conversion of convertible debt	483,219	8	483,211
Issuance of common stock upon conversion of convertible debt (in shares)		7,580,923
Equity component of convertible debt issuance, net of tax and issuance costs	113,053		113,053
Exercise of stock options and vesting of restricted stock units	27,404	1	27,403
Exercise of stock options and vesting of restricted stock units (in shares)		1,581,809
Shares issued in connection with employee stock purchase plan and 401(k) plan	5,767		5,767
Shares issued in connection with employee stock purchase plan and 401(k) plan (in shares)		135,280
Tax benefit on stock-based awards	12,861		12,861
Stock-based compensation	24,190		24,190
Balance at Sep. 30, 2013	$ 1,375,583	$ 74	$ 1,338,259	$ 42	$ 37,208
Balance (in shares) at Sep. 30, 2013		74,011,707