Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Revenues:
System and software	$ 737,790	$ 681,881	$ 631,549
Service and support	418,583	406,846	383,089
Total revenues	1,156,373	1,088,727	1,014,638
Cost of revenues:
System and software	65,288	64,280	54,972
Service and support	118,221	117,609	108,690
Amortization of purchased technology	3,598	7,801	9,796
Total cost of revenues	187,107	189,690	173,458
Gross profit	969,266	899,037	841,180
Operating expenses:
Research and development	348,817	313,962	310,758
Marketing and selling	342,799	338,653	326,608
General and administration	75,543	70,692	74,811
Equity in earnings of Frontline	(4,092)	(1,764)	(2,268)
Amortization of intangible assets	6,230	5,915	5,905
Special charges	16,929	9,946	13,174
Total operating expenses	786,226	737,404	728,988
Operating income	183,040	161,633	112,192
Other (expense) income, net	(520)	(1,432)	1,576
Interest expense	(19,452)	(18,866)	(31,444)
Income before income tax	163,068	141,335	82,324
Income tax expense (benefit)	9,510	2,701	(1,063)
Net income	153,558	138,634	83,387
Less: Loss attributable to noncontrolling interest	(1,700)	(102)	(485)
Net income attributable to Mentor Graphics shareholders	$ 155,258	$ 138,736	$ 83,872
Net income per share:
Basic (in dollars per share)	$ 1.33	$ 1.20	$ 0.76
Diluted (in dollars per share)	$ 1.29	$ 1.17	$ 0.74
Weighted average number of shares outstanding:
Basic (in shares)	113,671	110,998	110,138
Diluted (in shares)	116,702	114,017	112,915
Cash dividends declared per common share	$ 0.18	$ 0	$ 0