Revenue Recognition - Contract Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Short-term receivables	$ 71,707	$ 78,380
Long-term receivables	709	6,550
Short-term contract assets	1,751	2,102
Contract assets (noncurrent)	999	961
Short-term deferred revenue	19,828	20,584
Long-term deferred revenue	1,330	1,502
Contract Assets Rollforward
Contract with customer, assets	2,750	3,063
Reclassification to receivables, as the right to consideration becomes unconditional	(2,177)
Contract assets recognized, net of reclassification to receivables	1,864
Deferred Revenue Rollforward
Contract with customer, liability	21,158	22,086
Reclassification to revenue, as a result of performance obligations satisfied	(17,867)
Cash received in advance of satisfaction of performance obligations	16,939
Revenue recognized from performed obligations	$ 1,100	$ 18,000