Schedule II Valuation and Qualifying Accounts (Details) (Allowance for doubtful accounts, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 4,769,000	$ 1,853,000	$ 1,273,000
Additions	6,867,000	7,963,000	6,350,000
Deductions Write-offs	(3,490,000)	(5,047,000)	(5,770,000)
Balance at End of Year	$ 8,146,000	$ 4,769,000	$ 1,853,000