Summary of Signigicant Accounting Policies - Multi-client Data Library Costs and Accumulated Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Multi-client data library capitalized income	$ 9,300	$ 11,900	$ 12,700
Impairment of multi-client data library	$ 9,072	$ 0	$ 2,304