Acquisitions - Narrative (Details) - USD ($)			1 Months Ended		12 Months Ended
	Mar. 04, 2015	Jan. 13, 2015	Sep. 30, 2015	Mar. 31, 2015	Jan. 31, 2016	Jan. 25, 2015	Jan. 26, 2014	Jul. 26, 2015
Borrowings under line of credit				$ 35,000,000	$ 35,000,000	$ 5,000,000	$ 327,344,000
Goodwill					329,703,000	280,319,000
Triune Systems
Effective date of acquisition	Mar. 04, 2015
Name of acquired entity	Triune
Purchase price	$ 45,000,000
Cash paid to acquire business	35,000,000		$ 9,500,000
Remaining cash consideration to be paid	10,000,000				500,000
Earn-out liability	16,200,000				0
Acquisition consideration allocated to finite-lived intangile assets	12,000,000
Goodwill								$ 49,400,000
EnVerv
Effective date of acquisition		Jan. 13, 2015
Name of acquired entity		EnVerv, Inc.
Purchase price		$ 4,900,000
Goodwill						3,400,000
Core technologies | Triune Systems
Acquisition consideration allocated to finite-lived intangile assets								10,000,000
Core technologies | EnVerv
Acquisition consideration allocated to finite-lived intangile assets						$ 1,400,000
Customer relationships | Triune Systems
Acquisition consideration allocated to finite-lived intangile assets								$ 2,000,000
Contingent Consideration Arrangements Based on Annual Revenue Targets [Member] | Triune Systems
Potential payments under earn-out arrangements, high estimate	$ 70,000,000
Potential payment under earn-out arrangement for the first fiscal year					$ 13,000,000
Business Combination, Contingent Consideration Arrangements, Defined Earnout Period [Member] | Triune Systems
Period over which contingent consideration willl be paid	3 years
Contingent Consideration Based on Cumulative Revenue and Operating Income Targets | Triune Systems
Potential payments under earn-out arrangements, high estimate	$ 16,000,000