CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Class A Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2010	$ 527,815	$ 2	$ 87	$ 1,575,780	$ (1,045,563)	$ (2,491)
Balance (in shares) at Dec. 31, 2010		2,182	87,238
Increase (decrease) in stockholders' equity [Roll Forward]
Issuance of Common Stock in connection with exercise of stock options	28,503		2	28,501
Issuance of Common Stock in connection with exercise of stock options (in shares)			2,127
Common Stock tendered upon exercise of stock options in connection with employee tax obligations	(4,709)			(4,709)
Common Stock tendered upon exercise of stock options in connection with employee tax obligations (in shares)			(101)
Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution	3,405			3,405
Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution (in shares)			92
Issuance of restricted Common Stock under Long-Term Incentive Plan	0
Issuance of restricted Common Stock under Long-Term Incentive Plan (in shares)			5
Conversion of Class A Stock to Common Stock	0
Conversion of Class A Stock to Common Stock (in shares)		(55)	55
Stock-based compensation charges	27,385			27,385
Net income (loss) - basic and diluted	(105,952)				(105,952)
Other comprehensive (loss) income, net of tax	1,587					1,587
Balance at Jun. 30, 2011	478,034	2	89	1,630,362	(1,151,515)	(904)
Balance (in shares) at Jun. 30, 2011		2,127	89,416
Balance at Dec. 31, 2011	485,732	2	91	1,754,824	(1,267,323)	(1,862)
Balance (in shares) at Dec. 31, 2011		2,109	90,692
Increase (decrease) in stockholders' equity [Roll Forward]
Issuance of Common Stock in connection with exercise of stock options	39,634		3	39,631
Issuance of Common Stock in connection with exercise of stock options (in shares)			3,234
Common Stock tendered upon exercise of stock options in connection with employee tax obligations	(61,444)			(61,444)
Common Stock tendered upon exercise of stock options in connection with employee tax obligations (in shares)			(568)
Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution	0
Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution (in shares)			64
Issuance of restricted Common Stock under Long-Term Incentive Plan (in shares)			500
Conversion of Class A Stock to Common Stock	0
Conversion of Class A Stock to Common Stock (in shares)		(20)	20
Stock-based compensation charges	42,850			42,850
Net income (loss) - basic and diluted	88,394				88,394
Other comprehensive (loss) income, net of tax	(509)					(509)
Balance at Jun. 30, 2012	$ 594,657	$ 2	$ 94	$ 1,775,861	$ (1,178,929)	$ (2,371)
Balance (in shares) at Jun. 30, 2012		2,089	93,942