Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Net income	$ 25,123	$ 32,066	$ 48,451	$ 77,151
Other comprehensive income (loss), net of tax:
Change in unrealized gain (loss) on derivative instruments	211	251	(59)	349
Cash flow hedge reclassification adjustment for net loss included in net income	209	234	(58)	157
Cash flow hedges change net of reclassifications	2	17	(1)	192
Change in accumulated translation adjustment	3,947	4,439	(3,489)	(2,490)
Change in pension liability	(2)	(4)	(6)	(11)
Other comprehensive income (loss)	3,947	4,452	(3,496)	(2,309)
Comprehensive income	29,070	36,518	44,955	74,842
Net income (loss) attributable to noncontrolling interest	(412)	1,425	(1,271)	161
Change in accumulated translation adjustment attributable to the noncontrolling interest	(46)	(24)	2	(58)
Comprehensive loss attributable to the noncontrolling interest	(458)	1,401	(1,269)	103
Comprehensive income attributable to Mentor Graphics shareholders	$ 29,528	$ 35,117	$ 46,224	$ 74,739