Business Segments and Geographic Information - Asset Reconciliation (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Asset Reconciling Item [Line Items]
Total segment assets	$ 4,460,126	$ 4,317,534
Cash	283,524	32,463	$ 31,255
Deferred income tax assets	102,828	110,068
Operating Segments
Segment Reporting Asset Reconciling Item [Line Items]
Total segment assets	4,075,920	4,185,452	$ 4,122,830
Segment Reconciling Items
Segment Reporting Asset Reconciling Item [Line Items]
Cash	283,524	32,463
Deferred income tax assets	36,604	36,278
Restricted cash and investments, current and non-current	$ 64,078	$ 63,341