Revenue from Contracts with Customers - Contract Liabilities Table (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Change in Contracts with Customer, Liability [Roll Forward]
Balance at December 31, 2018		$ 145,624
Cash received or receivable, excluding revenues recognized during the period (1)	$ 15,800	44,365
Revenues recognized that were included in the contract liability balance at the beginning of the period (2)	(1,000)	(11,145)
Balance at September 30, 2019	178,844	178,844
Contract liabilities at September 30, 2019
Accrued liabilities			$ 6,631	$ 16,235
Other liabilities			172,213
Total contract liabilities from contracts with customers	$ 178,844	$ 145,624	$ 178,844	$ 145,624