Other Balance Sheet Accounts - Additional Information (Detail) (USD $) In Millions, unless otherwise specified		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Nov. 30, 2010	Oct. 31, 2014 Purchased intangible assets	Oct. 31, 2013 Purchased intangible assets	Oct. 31, 2014 Purchased intangible assets	Oct. 31, 2013 Purchased intangible assets	Oct. 31, 2014 Acquired intellectual property	Oct. 31, 2013 Acquired intellectual property	Oct. 31, 2014 Acquired intellectual property	Oct. 31, 2013 Acquired intellectual property	Oct. 31, 2014 Capitalized internal-use software development costs	Oct. 31, 2013 Capitalized internal-use software development costs	Oct. 31, 2014 Capitalized internal-use software development costs	Oct. 31, 2013 Capitalized internal-use software development costs	Oct. 31, 2014 Acquired developed technology	Oct. 31, 2013 Acquired developed technology	Oct. 31, 2014 Acquired developed technology	Oct. 31, 2013 Acquired developed technology
Finite-Lived Intangible Assets [Line Items]
Perpetual parking rights	$ 23.3
Capitalized software amortization expense										9.5	7.4	26.2	21.2	22.5	35.3	75.9	81.4
Capitalized stock based compensation										1.5	0.9	3.6	2.7
Amortization of acquired intangible assets		$ 14.9	$ 15.4	$ 44.9	$ 22.4	$ 1.2	$ 1.0	$ 3.6	$ 3.1