Convertible Preferred Stock (Tables)

6 Months Ended

Jun. 30, 2012

Convertible Preferred Stock [Abstract]

Convertible preferred stock balances

As of June 30, 2012, convertible preferred stock balances were as follows:

	Shares		Shares Issued				Liquidation
(in thousands, except share information)	Authorized		and Outstanding		Carrying Value		Amount
Series A		1,527,611		1,527,611	$	1,835	$	2,200
Series B-1		3,425,152		3,425,152		4,726		4,932
Series B-2		14,811,323		14,672,434		21,039		21,128
Series C		6,944,450		6,944,450		19,905		20,000
Series D		11,385,195		11,385,195		35,673		37,002
Series E		22,058,823		5,955,881		18,845		20,250
		60,152,554		43,910,723	$	102,023	$	105,512