Restatement - Income Statement (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Revenues:
Service revenues	$ 362,187,000	[1]	$ 314,334,000	[1]	$ 703,728,000	[1]	$ 606,972,000	[1]
Reimbursable expenses	16,576,000		12,273,000		28,211,000		22,618,000
Total gross revenues	378,763,000		326,607,000		731,939,000		629,590,000
Operating expenses:
Project personnel expenses	246,386,000		212,213,000		490,955,000		419,635,000
Reimbursable expenses	16,576,000		12,273,000		28,211,000		22,618,000
Total project personnel expenses and reimbursable expenses	262,962,000		224,486,000		519,166,000		442,253,000
Selling and marketing expenses	15,172,000		12,953,000		30,757,000		24,703,000
General and administrative expenses	59,548,000		53,696,000		117,505,000		107,875,000
Restructuring and other related charges			(31,000)				1,983,000
Amortization of purchased intangible assets	3,822,000		3,263,000		7,041,000		6,920,000
Acquisition costs and other related charges	46,000		(1,284,000)		428,000		(384,000)
Impairment of intangible asset	0		0		0		1,494,000
Total operating expenses	343,421,000		293,083,000		676,761,000		584,844,000
Income from operations	35,342,000		33,524,000		55,178,000		44,746,000
Interest income	2,053,000		1,570,000		4,009,000		3,076,000
Interest expense	(820,000)		(666,000)		(1,488,000)		(1,360,000)
Other income, net	101,000		296,000		471,000		356,000
Income before income taxes	36,676,000		34,724,000		58,170,000		46,818,000
Provision for income taxes	13,431,000		11,972,000		21,336,000		18,197,000
Net income	23,245,000		22,752,000		36,834,000		28,621,000
Less: Net loss attributable to noncontrolling interest	(41,000)		(41,000)		(77,000)		(87,000)
Net income attributable to stockholders of Sapient Corporation	23,286,000		22,793,000		36,911,000		28,708,000
Basic net income per share attributable to stockholders of Sapient Corporation (in dollars per share)	$ 0.16		$ 0.16		$ 0.26		$ 0.21
Diluted net income per share attributable to stockholders of Sapient Corporation (in dollars per share)	$ 0.16		$ 0.16		$ 0.26		$ 0.20
Weighted average common shares (in shares)	141,850		138,791		141,135		138,112
Weighted average dilutive common share equivalents (in shares)	2,202		4,110		2,652		4,446
Weighted average common shares and dilutive common share equivalents (in shares)	144,052		142,901		143,787		142,558
As Reported [Member]
Revenues:
Service revenues			314,334,000				606,972,000
Reimbursable expenses			12,273,000				22,618,000
Total gross revenues			326,607,000				629,590,000
Operating expenses:
Project personnel expenses			211,536,000				418,281,000
Reimbursable expenses			12,273,000				22,618,000
Total project personnel expenses and reimbursable expenses			223,809,000				440,899,000
Selling and marketing expenses			12,994,000				24,786,000
General and administrative expenses			53,519,000				107,521,000
Restructuring and other related charges			(31,000)				1,983,000
Amortization of purchased intangible assets			3,263,000				6,920,000
Acquisition costs and other related charges			(1,284,000)				(384,000)
Impairment of intangible asset			0				1,494,000
Total operating expenses			292,270,000				583,219,000
Income from operations			34,337,000				46,371,000
Interest income			1,570,000				3,076,000
Interest expense			(666,000)				(1,360,000)
Other income, net			296,000				356,000
Income before income taxes			35,537,000				48,443,000
Provision for income taxes			12,250,000				18,626,000
Net income			23,287,000				29,817,000
Less: Net loss attributable to noncontrolling interest			(41,000)				(87,000)
Net income attributable to stockholders of Sapient Corporation			23,328,000				29,904,000
Basic net income per share attributable to stockholders of Sapient Corporation (in dollars per share)			$ 0.17				$ 0.22
Diluted net income per share attributable to stockholders of Sapient Corporation (in dollars per share)			$ 0.16				$ 0.21
Weighted average common shares (in shares)			138,791				138,112
Weighted average dilutive common share equivalents (in shares)			4,110				4,446
Weighted average common shares and dilutive common share equivalents (in shares)			142,901				142,558
Adjustments [Member]
Revenues:
Service revenues			0				0
Reimbursable expenses			0				0
Total gross revenues			0				0
Operating expenses:
Project personnel expenses			677,000				1,354,000
Reimbursable expenses			0				0
Total project personnel expenses and reimbursable expenses			677,000				1,354,000
Selling and marketing expenses			(41,000)				(83,000)
General and administrative expenses			177,000				354,000
Restructuring and other related charges			0				0
Amortization of purchased intangible assets			0				0
Acquisition costs and other related charges			0				0
Impairment of intangible asset			0				0
Total operating expenses			813,000				1,625,000
Income from operations			(813,000)				(1,625,000)
Interest income			0				0
Interest expense			0				0
Other income, net			0				0
Income before income taxes			(813,000)				(1,625,000)
Provision for income taxes			(278,000)				(429,000)
Net income			(535,000)				(1,196,000)
Less: Net loss attributable to noncontrolling interest			0				0
Net income attributable to stockholders of Sapient Corporation			$ (535,000)				$ (1,196,000)
Basic net income per share attributable to stockholders of Sapient Corporation (in dollars per share)			$ (0.01)				$ (0.01)
Diluted net income per share attributable to stockholders of Sapient Corporation (in dollars per share)			$ 0.00				$ (0.01)
Weighted average common shares (in shares)			0				0
Weighted average dilutive common share equivalents (in shares)			0				0
Weighted average common shares and dilutive common share equivalents (in shares)			0				0

[1] Allocation of service revenues to individual countries is based on the location of the Sapient legal entity that contracts with the client.