Business Segments - Additional Information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment									3
Service revenues	$ (1,304,086)	$ (1,189,897)	$ (1,108,326)	$ (1,506,691)	$ (1,537,385)	$ (1,552,132)	$ (1,516,385)	$ (1,468,530)	$ (5,109,000)	$ (6,074,432)	$ (5,800,271)
Elimination of intersegment revenues
Segment Reporting Information [Line Items]
Service revenues									$ 239,996	$ 172,439	$ 132,381