Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2018	Jan. 01, 2018
Contract assets from customers	$ 1,496	$ 1,344	$ 1,496	$ 1,300
Contract liabilities from customers	285	52	285	100
Significant changes in the contract assets balances
Beginning balance		1,344
Revenue recognized from performance obligations satisfied in the current period		1,386
Transferred to accounts receivables from contract assets recognized at the beginning of the period		(1,145)
Other		(89)
Ending balance	1,496	1,496
Significant changes in the contract liability balances
Beginning balance		52
Revenue recognized from performance obligations satisfied in the current period		(39)
Contract liabilities recognized related to upfront license fees		300
Other		(28)
Ending balance	285	285
Impairment of contract assets or receivables from contracts with customers	0	0
Revenue recognized for variable consideration under license arrangements	$ 500	$ 1,300
Royalty license contracts with customers
Remainder of 2018			469
2019			1,760
2020			1,743
2021			1,035
2022			283
Total			5,290
Factored Accounts Receivable
Receivables from contracts with customers			$ 700	$ 300