Redeemable Convertible Preferred Stock (Tables)

6 Months Ended

Jun. 30, 2012

Series C Redeemable Convertible Preferred Stock [Member]

Temporary Equity [Line Items]

Fair Value Inputs

	June 30, 2012		December 31, 2011
Risk free interest rate	0.3	%	0.3	%
Expected volatility	42.0	%	41.0	%
Expected life (in years)	2		2
Dividend yield	—	%	—	%

Series D Redeemable Convertible Preferred Stock [Member]

Temporary Equity [Line Items]

Fair Value Inputs

	June 30, 2012		December 31, 2011
Risk free interest rate	0.4	%	0.4	%
Expected volatility	41.2	%	42.9	%
Expected life (in years)	3		3
Dividend yield	—	%	—	%