Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Summary of financial assets measured at fair value on a recurring basis

The following table summarizes the Company's assets at fair value on a recurring basis at December 31, 2016 and 2015 by level within the fair value hierarchy. There were no liabilities measure at fair value on a recurring basis at December 31, 2016 and 2015. These assets are classified in their entirety based on the lowest level of input that is significant to the fair value measurement (in thousands):



	At December 31, 2016								At December 31, 2015
							Total Fair								Total Fair
	Level 1		Level 2		Level 3		Value		Level 1		Level 2		Level 3		Value
Assets:
Cash equivalents	$	107,721	$	—	$	—	$	107,721	$	112,131	$	—	$	—	$	112,131
Total Assets	$	107,721	$	—	$	—	$	107,721	$	112,131	$	—	$	—	$	112,131

Summary of changes in the allowance for doubtful accounts and sales allowances

The following table summarizes the changes in the allowance for doubtful accounts and sales allowances (in thousands):



	Year Ended December 31,
	2016			2015			2014
Allowances, at beginning of period	$	2,720		$	2,069		$	2,184
Charged as a reduction of revenue	7,042			6,716			4,797
Charged to bad debt expense in general and administrative expenses	1,285			925			373
Write-offs, net of recoveries	(8,447		)	(6,990		)	(5,285		)
Allowances, at end of period	$	2,600		$	2,720		$	2,069

Schedule of expected amortization expense with respect to capitalized software costs

Expected amortization expense with respect to capitalized software costs at December 31, 2016 for each of the three years through December 31, 2019 is as follows (in thousands):



Years ended December 31,
2017	$	12,438
2018	5,931
2019	2,024
2020	23
Total amortization expense	$	20,416