Revenue from Contracts with Customers - Contract Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Revenue from External Customer [Line Items]
Contract liabilities	$ 189,134	$ 167,832
Prepaid expenses and other current assets / other assets, net
Revenue from External Customer [Line Items]
Contract assets, current	102,945	105,499
Contract assets	6,000		$ 6,000
Accounts receivable, net
Revenue from External Customer [Line Items]
Contract assets, current	350,537	539,806
Other assets, net
Revenue from External Customer [Line Items]
Contract assets, noncurrent	$ 37,450	$ 38,250