Restructuring - Restructuring and Related Costs (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 1,474		$ 1,659	$ 12,404	$ 6,632
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring expense	1,250		1,556	1,250	5,719
Reduction in force - other
Restructuring Cost and Reserve [Line Items]
Restructuring expense	224			224
Joint venture workforce services rendered
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0			8,218
Professional and other costs
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	$ 2,712		2,712
Joint Venture
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 1,474	$ 10,930		$ 12,404
Asset write-downs & other costs
Restructuring Cost and Reserve [Line Items]
Restructuring expense			103		913
Facility Closing
Restructuring Cost and Reserve [Line Items]
Restructuring expense			$ 1,659		$ 6,632	$ 759