Fair Value Measurements - Financial Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jan. 29, 2017	Jan. 31, 2016
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	$ 1,425	$ 0
Agency securities | Level 1
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	16,945	16,866
Recurring
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Derivative financial instruments - asset	326	0
Total financial assets	18,696	16,866
Derivative financial instruments - liability	0	0
Total financial liabilities	1,242	1,457
Recurring | Level 1
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Derivative financial instruments - asset	0	0
Total financial assets	16,945	16,866
Derivative financial instruments - liability	0	0
Total financial liabilities	0	0
Recurring | Level 2
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Derivative financial instruments - asset	326	0
Total financial assets	326	0
Derivative financial instruments - liability	0	0
Total financial liabilities	0	0
Recurring | Level 3
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Derivative financial instruments - asset	0	0
Total financial assets	1,425	0
Derivative financial instruments - liability	0	0
Total financial liabilities	1,242	1,457
Recurring | Agency securities
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	16,945	16,866
Recurring | Agency securities | Level 1
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	16,945	16,866
Recurring | Agency securities | Level 2
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring | Agency securities | Level 3
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring | Convertible debt
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	1,425	0
Recurring | Convertible debt | Level 1
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring | Convertible debt | Level 2
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring | Convertible debt | Level 3
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Available-for-sale securities	1,425	0
Triune Systems | Recurring
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Earn-out liability	0	0
Triune Systems | Recurring | Level 1
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Earn-out liability	0	0
Triune Systems | Recurring | Level 2
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Earn-out liability	0	0
Triune Systems | Recurring | Level 3
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Earn-out liability	0	0
Cycleo [Member] | Recurring
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Earn-out liability	1,242	1,457
Cycleo [Member] | Recurring | Level 1
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Earn-out liability	0	0
Cycleo [Member] | Recurring | Level 2
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Earn-out liability	0	0
Cycleo [Member] | Recurring | Level 3
Fair Value, Assets Measured On A Recurring Basis [Line Items]
Earn-out liability	$ 1,242	$ 1,457