Segment Data - Disaggregated Revenues, Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 202,763	$ 235,329	$ 630,648	$ 698,884
Operating segments | Mats and integrated services
Disaggregation of Revenue [Line Items]
Revenues	50,216	54,359	144,904	160,797
Operating segments | Mats and integrated services | Service revenues
Disaggregation of Revenue [Line Items]
Revenues	18,930	22,989	59,989	68,740
Operating segments | Mats and integrated services | Rental revenues
Disaggregation of Revenue [Line Items]
Revenues	16,700	19,911	55,955	59,661
Operating segments | Mats and integrated services | Product sales revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 14,586	$ 11,459	$ 28,960	$ 32,396