Commitments and Contingencies (Details) $ in Millions	Mar. 31, 2016 USD ($)
Commitments and Contingencies [Abstract]
Purchase Commitments Related to Capital Expansion Plan	$ 76.2

Commitment for contractual purchases related to facility development and expansion.

No definition available.

Name:	ctsh_PurchaseCommitmentsRelatedtoCapitalExpansionPlan
Namespace Prefix:	ctsh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant