Revenue from Contracts with Customers - Contract Assets Table (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Change in Contracts with Customer, Asset [Roll Forward]
Balance at December 31, 2018	$ 47,621
Amounts transferred to Accounts receivable, net that were included in the contract assets balance at the beginning of the period	(1,376)
Additional estimated revenues recognized	3,810
Balance at March 31, 2019	50,055
Contract assets at March 31, 2019
Other current assets		$ 7,172	$ 5,399
Other assets		42,883
Total contract assets from contracts with customers	$ 47,621	$ 50,055	$ 47,621