Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012
Net income	$ 23,747	$ 17,555	$ 23,328	$ 45,085
Other comprehensive income (loss), net of tax:
Change in unrealized gain (loss) on derivative instruments	(15)	(702)	(270)	98
Cash flow hedge reclassification adjustment for net loss included in net income	(23)	(424)	(267)	(77)
Cash flow hedges change net of reclassifications	8	(278)	(3)	175
Change in accumulated translation adjustment	(2,119)	(6,148)	(7,436)	(6,929)
Change in pension liability	(2)	(4)	(4)	(7)
Other comprehensive loss	(2,113)	(6,430)	(7,443)	(6,761)
Comprehensive income	21,634	11,125	15,885	38,324
Net loss attributable to noncontrolling interest	(235)	(612)	(859)	(1,264)
Change in accumulated translation adjustment attributable to the noncontrolling interest	5	(13)	48	(34)
Comprehensive loss attributable to the noncontrolling interest	(230)	(625)	(811)	(1,298)
Comprehensive income attributable to Mentor Graphics shareholders	$ 21,864	$ 11,750	$ 16,696	$ 39,622