Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Apr. 30, 2013	Apr. 30, 2012
Revenues:
System and software	$ 123,284	$ 149,356
Service and support	103,231	98,562
Total revenues	226,515	247,918
Cost of revenues:
System and software	8,899	14,790
Service and support	30,075	28,414
Amortization of purchased technology	1,207	2,179
Total cost of revenues	40,181	45,383
Gross profit	186,334	202,535
Operating expenses:
Research and development	79,717	71,046
Marketing and selling	79,107	79,752
General and administration	18,277	16,649
Equity in earnings of Frontline	(397)	(587)
Amortization of intangible assets	1,654	1,706
Special charges	2,083	1,147
Total operating expenses	180,441	169,713
Operating income	5,893	32,822
Other income (expense), net	(959)	83
Interest expense	(4,785)	(4,594)
Income before income tax	149	28,311
Income tax expense	568	781
Net income (loss)	(419)	27,530
Net loss attributable to noncontrolling interest	(624)	(652)
Net income attributable to Mentor Graphics shareholders	$ 205	$ 28,182
Net income per share:
Basic (in dollars per share)	$ 0.01	$ 0.26
Diluted (in dollars per share)	$ 0.01	$ 0.25
Weighted average number of shares outstanding:
Basic (in shares)	112,711	109,907
Diluted (in shares)	115,751	113,243
Common Stock, Dividends, Per Share, Declared	$ 0.045	$ 0.000