Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Other Liabilities, Noncurrent [Abstract]
Contract liabilities, net of current portion	$ 33,217	$ 34,866
Asset retirement obligations	8,623	7,647
Deferred payments related to acquisitions	0	715
Other	2,877	2,827
Other long-term liabilities	$ 44,717	$ 46,055