Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2013

Accounting Policies [Abstract]

Schedule of Black-Scholes Option-Pricing Model Assumptions

nformation represents the weighted average of the assumptions used in the Black-Scholes option-pricing model:

	For the Years Ended December 31,
	2013		2012		2011
Risk-free interest rate	1.5	%	1.0	%	1.7	%
Expected term (in years)	6.0		5.8		6.0
Estimated dividend yield	—	%	—	%	—	%
Estimated volatility	51.5	%	53.9	%	56.9	%

Reconciliation of Beginning and Ending Amount of Allowance for Doubtful Accounts

A reconciliation of the beginning and ending amount of allowance for doubtful accounts for the years ended December 31, 2013, 2012 and 2011, is as follows (in thousands):

	2013			2012			2011
Beginning balance, January 1	$	464		$	153		$	32
Additions and adjustments	968			358			203
Write-offs	(411		)	(47		)	(82		)
Ending balance, December 31	$	1,021		$	464		$	153