Fair Value Measurements - Financial Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jul. 26, 2015	Jan. 25, 2015
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	$ 16,859	$ 23,271
Interest rate cap	0	33
Total financial assets	16,859	23,304
Total financial liabilities	18,387	1,619
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	16,859	23,271
Interest rate cap	0	0
Total financial assets	16,859	23,271
Total financial liabilities	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Interest rate cap	0	33
Total financial assets	0	33
Total financial liabilities	0	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Interest rate cap	0	0
Total financial assets	0	0
Total financial liabilities	18,387	1,619
Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	16,859	23,271
Cash Equivalents [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	16,859	23,271
Cash Equivalents [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Cash Equivalents [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Triune Systems [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	16,930	0
Triune Systems [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Triune Systems [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Triune Systems [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	16,930	0
Cycleo [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	1,457	1,619
Cycleo [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Cycleo [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Cycleo [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	$ 1,457	$ 1,619