Overview and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) Segment CompensationPlan	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of reportable segments | Segment	2
Percentage of total consolidated revenues representing fulfillment services contracts	1.60%	1.40%	1.30%
Cash and cash equivalents	$ 235,358	$ 215,137	$ 211,985	$ 187,322
Interest bearing investments, original maturities	Less than 90 days
Tax position measurement	Greater than 50%
Period over which up-front fees, included within deferred revenue, are earned	12 months
Number of stock-based compensation plan | CompensationPlan	3
Fair value discount rate	14.00%
Minimum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Deferred revenue recognition period	30 days
Non-deliverable forward contracts and options expiring period	1 month
Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Deferred revenue recognition period	7 years
Non-deliverable forward contracts and options expiring period	24 months
Equipment [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Useful life of equipment	5 years
International Operations [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Cash and cash equivalents	$ 221,700	$ 194,400
Qelp [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Acquisition date	Jul. 02, 2015