Fair Value Measurements - Financial Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jul. 30, 2017	Jan. 29, 2017
Agency Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	$ 10,097	$ 16,945
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative financial instruments (asset)	1,326	326
Total financial assets	12,598	18,696
Derivative financial instruments (liability)	0	0
Total financial liabilities	18,242	1,242
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative financial instruments (asset)	0	0
Total financial assets	10,097	16,945
Derivative financial instruments (liability)	0	0
Total financial liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative financial instruments (asset)	1,326	326
Total financial assets	1,326	326
Derivative financial instruments (liability)	0	0
Total financial liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative financial instruments (asset)	0	0
Total financial assets	1,175	1,425
Derivative financial instruments (liability)	0	0
Total financial liabilities	18,242	1,242
Fair Value, Measurements, Recurring [Member] | Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	10,097	16,945
Fair Value, Measurements, Recurring [Member] | Agency Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	10,097	16,945
Fair Value, Measurements, Recurring [Member] | Agency Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Agency Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Convertible debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	1,175	1,425
Fair Value, Measurements, Recurring [Member] | Convertible debt | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Convertible debt | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] | Convertible debt | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	1,175	1,425
Fair Value, Measurements, Recurring [Member] | AptoVision Technologies Inc. [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	17,000	0
Fair Value, Measurements, Recurring [Member] | AptoVision Technologies Inc. [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Fair Value, Measurements, Recurring [Member] | AptoVision Technologies Inc. [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Fair Value, Measurements, Recurring [Member] | AptoVision Technologies Inc. [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	17,000	0
Fair Value, Measurements, Recurring [Member] | Triune Systems [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Fair Value, Measurements, Recurring [Member] | Triune Systems [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Fair Value, Measurements, Recurring [Member] | Triune Systems [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Fair Value, Measurements, Recurring [Member] | Triune Systems [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Fair Value, Measurements, Recurring [Member] | Cycleo [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	1,242	1,242
Fair Value, Measurements, Recurring [Member] | Cycleo [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Fair Value, Measurements, Recurring [Member] | Cycleo [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	0	0
Fair Value, Measurements, Recurring [Member] | Cycleo [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Earn-out liability	$ 1,242	$ 1,242