Revenue from Contracts with Customers - Assets and Liabilities Rollforward (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended |
---|---|---|
Jun. 30, 2019 |
Jun. 30, 2019 |
|
Revenue from Contract with Customer [Abstract] | ||
Revenue recognized that was included in contract liabilities at beginning of period | $ 574 | $ 1,305 |
Increase in contract liabilities due to cash received, excluding amounts recognized as revenue | (500) | (661) |
Transferred to receivables from contract assets at beginning of period | $ 0 | $ 0 |