Revenue from Contracts with Customers - Contract Assets Table (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 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	(4,841)
Additional estimated revenues recognized	14,698
Cumulative catch-up adjustment for change in estimated consideration due to an annual cost-of-service rate update	9,879
Balance at December 31, 2019	67,357
Contract assets at December 31, 2019
Other current assets		$ 7,129	$ 5,399
Other assets		60,228
Total contract assets from contracts with customers	$ 67,357	$ 67,357	$ 47,621