Discontinued Operations and Assets Held for Sale - Balance Sheet Components of Discontinued Operations (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets
Current assets held for sale	$ 2,323	$ 790
Long-term assets
Long-term assets held for sale	0	1,584
Current liabilities
Total current liabilities for sale	214	246
Long-term liabilities
Long-term liabilities held for sale	0	81
CoSense and NFI [Member] | Discontinued Operations, Held-for-sale [Member]
Current assets
Accounts receivable	153	130
Inventory	652	660
Property & equipment, net	32	0
Goodwill	718	0
Other intangible assets	768	0
Current assets held for sale	2,323	790
Long-term assets
Property & equipment, net	0	48
Goodwill	0	718
Other intangible assets	0	818
Long-term assets held for sale	0	1,584
Current liabilities
Accounts payable	48	127
Accrued compensation and other current liabilities	135	119
Other long-term liabilities	31	0
Total current liabilities for sale	214	246
Long-term liabilities
Other long-term liabilities	0	81
Long-term liabilities held for sale	$ 0	$ 81