Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Revenues:
System and software	$ 178,115	$ 170,835	$ 475,824	$ 444,322
Service and support	114,568	104,807	329,243	311,051
Total revenues	292,683	275,642	805,067	755,373
Cost of revenues:
System and software	11,821	15,947	54,977	40,082
Service and support	33,670	29,396	93,684	88,380
Amortization of purchased technology	2,050	729	5,252	2,648
Total cost of revenues	47,541	46,072	153,913	131,110
Gross profit	245,142	229,570	651,154	624,263
Operating expenses:
Research and development	96,269	86,799	268,262	246,823
Marketing and selling	89,875	85,746	256,814	244,664
General and administration	19,851	18,917	57,006	52,452
Equity in earnings of Frontline	(1,184)	(1,392)	(4,625)	(2,739)
Amortization of intangible assets	2,233	1,440	6,009	4,650
Special charges	8,375	4,688	19,409	12,570
Total operating expenses	215,419	196,198	602,875	558,420
Operating income	29,723	33,372	48,279	65,843
Other income (expense), net	(381)	352	(743)	(879)
Interest expense	(4,934)	(4,967)	(14,326)	(14,649)
Income before income tax	24,408	28,757	33,210	50,315
Income tax expense	3,849	3,634	1,907	1,864
Net income	20,559	25,123	31,303	48,451
Less: Loss attributable to noncontrolling interest	(471)	(412)	(1,348)	(1,271)
Net income attributable to Mentor Graphics shareholders	$ 21,030	$ 25,535	$ 32,651	$ 49,722
Net income per share:
Basic	$ 0.18	$ 0.21	$ 0.30	$ 0.40
Diluted	$ 0.18	$ 0.20	$ 0.29	$ 0.39
Weighted average number of shares outstanding:
Basic	114,405	113,986	114,399	113,232
Diluted	116,715	117,078	116,928	116,395
Cash dividends declared per common share	$ 0.050	$ 0.045	$ 0.150	$ 0.135