Goodwill - Changes In Carrying Amount Of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Balance at the beginning of year	$ 7,157
Impairment loss	(6,689)	$ 0	$ 0
Balance at the end of year	0	7,157
Well Intervention
Goodwill [Line Items]
Balance at the beginning of year	7,157	0
Additions		6,855
Impairment loss	(6,689)
Other adjustments	(468)	302
Balance at the end of year	$ 0	$ 7,157	$ 0