Contract Assets and Liabilities Changes in Net Contract Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Contract assets
Contract asset, current	$ 1,145	$ 325
Contract asset, non-current	188	0
Contract asset	1,333	325
Contract Liabilities
Contract liability, current	5,963	2,252
Contract liability, non-current	1,401	4,442
Contract liabilities	$ 7,364	$ 6,694

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

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