Income Taxes - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended				12 Months Ended							3 Months Ended										3 Months Ended	12 Months Ended	3 Months Ended						1 Months Ended	3 Months Ended
	Jul. 13, 2011	Mar. 31, 2013	Sep. 30, 2012	Mar. 31, 2012	Sep. 30, 2010	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2007	Dec. 31, 2005	Dec. 31, 2004	Dec. 31, 2003	Dec. 31, 2002	Mar. 31, 2013 Finance Bill 2013	Mar. 31, 2013 Finance Bill 2013 Maximum	Mar. 31, 2013 Finance Bill 2013 Surcharge Minimum	Mar. 31, 2012 Finance Bill 2013 Corporation earning more than Indian Rupees 10Mn	Mar. 31, 2013 Finance Bill 2013 Corporation earning more than Indian Rupees 10Mn	Dec. 31, 2009 Software Development Entity	Apr. 30, 2008 Tax Exemption Period Entity	Mar. 31, 2013 Mumbai Tax Exemption Period Entity	Mar. 31, 2013 Mumbai Completion of Tax Holiday Period Entity	Mar. 31, 2013 Minimum Alternate Tax (MAT)	Mar. 31, 2013 Syntel Europe Limited	Dec. 31, 2012 Syntel Europe Limited	Mar. 31, 2013 Certain Units In Sez First Five Years	Mar. 31, 2013 Certain Units In Sez Additional Two Years	Mar. 31, 2013 Certain Units In Sez Additional Three Years	Mar. 31, 2013 New Units In Sez First Five Years	Mar. 31, 2013 New Units In Sez Next Five Years	Mar. 31, 2013 New Units In Sez Another Five Years	Apr. 30, 2008 Three Units in Mumbai First Five Years	Mar. 31, 2013 Three Units in Mumbai First Five Years	Mar. 31, 2013 Unit in Chennai First Five Years Entity	Mar. 31, 2013 Other Disputes
Income Taxes [Line Items]
Statutory rate		35.00%		35.00%
Expense recognized for accrued interest and penalties		$ 70,000
Accrued interest and penalties related to unrecognized tax benefits		1,470,000					1,400,000
Income taxes paid against liabilities for unrecognized tax benefits		22,760,000					20,580,000
Unrecognized tax liability		27,150,000					24,940,000
Unrecognized tax benefits, tax disputes		1,670,000
Unrecognized tax benefits, potential tax disputes		3,170,000
Corporate income taxes, exemption percentage																									100.00%	50.00%	50.00%	100.00%	50.00%	50.00%	50.00%	100.00%	100.00%
Number of units																		1	4	6	1												1
Exemption from corporate income taxes		10 years
Corporate income taxes, years		15 years
Unrecognized Indian income tax liabilities											5,040,000	5,040,000																						1,660,000
Income tax liability recognized									810,000	810,000																								860,000
Income tax adjustments provision reversal						330,000
Reversal of provision of uncertain tax liability		240,000
Incurred losses of subsidiary																							2,170,000	1,960,000
Deferred tax assets																							450,000	430,000
Valuation allowance																							450,000	430,000
Branch Profit Tax (BPT)		15.00%
Accumulated deferred tax liability on BPT								1,730,000
Additional branch profit taxes if profits were not permanently invested		5,850,000
Accrued taxes, likely amount		190,100,000
Income tax audit, service tax objection amount		5,930,000	530,000		3,850,000
Service tax audit objection received	3,000,000
Closure of service tax audit objection amount		850,000
Received service tax refund		170,000
Service tax return with show cause notice		2,230,000
Service tax demand including penalty		4,320,000
Interest percentage on service tax penalty		18.00%
Surcharge rate													5.00%				10.00%
Corporation tax rate													33.99%			32.445%
Change in effective tax rate due to increase in surcharge														1.00%	0.75%
Local tax liability gross		190,000					4,300,000
Local tax liability net							2,700,000
Minimum alternate tax credit expiration period																						10 years
Minimum Alternate tax credit																						$ 17,550,000