Business Combinations - Additional Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended					12 Months Ended			12 Months Ended		1 Months Ended		1 Months Ended
	Aug. 30, 2011	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010	Jan. 31, 2012 Purchased Technologies	Jan. 31, 2012 Purchased Technologies Minimum Year	Jan. 31, 2012 Purchased Technologies Maximum Year	Jan. 31, 2012 Other Intangible Assets	Jan. 31, 2012 Other Intangible Assets Minimum Year	Jan. 31, 2012 Other Intangible Assets Maximum Year	Mar. 18, 2010 Valor	Jan. 31, 2011 Valor	Mar. 18, 2010 Valor Purchased Technologies Year	Mar. 18, 2010 Valor Other Intangible Assets Year
Business Acquisition [Line Items]
Fair value of net assets of acquired business	$ 8,900
Identifiable Intangible Assets Acquired		13,110	24,900	9,960	5,980			7,130				18,600	12,300	6,300
Intangible assets, amortization period						3	4		3	5			3
Shares of common stock issued											5,621
Business acquisition, cash paid											32,715
Fair value of common stock issued											47,163
Closing price per share of common stock issued to former common shareholders											$ 8.39
Consideration for business acquisition											7,025
Fair value of the Frontline investment											29,500
Cash acquired											$ 27,110
Intangible assets, amortization period minimum														1
Intangible assets, amortization period maximum														4