Stockholders' Equity - Schedule of Stock-Based Compensation Recorded in Expense Categories (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total allocated share-based compensation expense	$ 2,224	$ 1,983	$ 5,885	$ 5,148
Cost of Services and Fulfillment [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total allocated share-based compensation expense	1,183	1,134	3,218	3,005
Selling and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total allocated share-based compensation expense	331	302	754	767
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total allocated share-based compensation expense	$ 710	$ 547	$ 1,913	$ 1,376