Income Taxes (Tables)

12 Months Ended

Dec. 31, 2011

Income Taxes [Abstract]

Deferred Tax Assets

The tax effect of temporary differences, net operating loss carry-forwards, and research and experimental and other tax credit carry-forwards as of December 31, 2011 and 2010 is as follows:

		2011	2010
Deferred tax assets:
	Net operating loss carry-forward	$282,480	$243,893
	Fixed assets	14,847	13,600
	Deferred revenue	120,490	70,443
	Deferred compensation	47,092	39,120
	Research and experimental and other tax credit carry-forwards	67,734	45,588
	Capitalized research and development costs	31,371	38,865
	Other	15,956	10,863
		579,790	462,372
Deferred tax liabilities:
	Convertible senior notes	(1,428)
Net deferred tax assets:		578,542
Valuation allowance		(578,542)	(462,372)
		--	--

Unrecognized Tax Benefits

The following table summarizes the gross amounts of unrecognized tax benefits at the beginning and end of 2011 and 2010:

	2011	2010
Balance as of January 1	$12,819	$         -
Gross increases related to current year tax positions	2,192	3,550
Gross increases related to prior year tax positions		9,269
Gross decreases due to settlements	(9,415)	_____
Balance as of December 31	$5,596	$12,819