Stockholders' Equity - Summary of Stock-Based Compensation Recorded in Expense Categories (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total allocated share-based compensation expense	$ 1,947	$ 1,860
Cost of Services and Fulfillment [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total allocated share-based compensation expense	1,073	904
Selling and Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total allocated share-based compensation expense	338	422
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total allocated share-based compensation expense	$ 536	$ 534