Overview and Summary of Significant Accounting Policies - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2012 CompensationPlan Segment	Sep. 30, 2011
Number of reportable segments	2
Percentage of total consolidated revenues representing fulfillment services contracts	1.40%	1.50%
Tax position measurement	Greater than 50%
Number of stock based compensation plan	3
Non deliverable forward contracts and options expiring period minimum	1 month
Non deliverable forward contracts and options expiring period maximum	24 months