Debt and Finance Leases - Senior Secured Credit Facilities - Narrative (Details) - USD ($)		1 Months Ended	12 Months Ended
	Nov. 17, 2017	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Debt issuance costs			$ 3,514,000	$ 0	$ 7,025,000
Credit Facility
Line of Credit Facility [Line Items]
Change on interest rate margin		1.25%
Debt issuance costs		$ 4,000,000
Third party fees		$ 4,000,000
Credit Facility | Revolving Credit Facility
Line of Credit Facility [Line Items]
Available borrowing capacity			87,000,000
Amount of letters of credit outstanding			33,000,000
Credit Facility | Term A-1 Loan Facility borrowings maturing through November 2022 bearing interest at LIBOR plus 3.75%, interest rate of 5.54% at December 31, 2019
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 230,000,000
Credit Facility | Term A-2 Loan Facility borrowings maturing through November 2024 bearing interest at LIBOR plus 3.40% (after consideration of 0.60% patronage benefit), interest rate of 5.19% at December 31, 2019
Line of Credit Facility [Line Items]
Maximum borrowing capacity	450,000,000
Credit Facility | U.S. Revolver of $84 million maturing in November 2022, $39 million available, bearing interest at LIBOR plus 3.75% at December 31, 2019
Line of Credit Facility [Line Items]
Maximum borrowing capacity	100,000,000		84,000,000
Available borrowing capacity	84,000,000		39,000,000
Credit Facility | Multi-currency Revolver of $126 million maturing in November 2022, $48 million available, bearing interest at LIBOR plus 3.75% at December 31, 2019
Line of Credit Facility [Line Items]
Maximum borrowing capacity	150,000,000		126,000,000
Available borrowing capacity	$ 126,000,000		$ 48,000,000
Credit Facility | LIBOR | Term A-1 Loan Facility borrowings maturing through November 2022 bearing interest at LIBOR plus 3.75%, interest rate of 5.54% at December 31, 2019
Line of Credit Facility [Line Items]
Basis spread			3.75%
Credit Facility | LIBOR | U.S. Revolver of $84 million maturing in November 2022, $39 million available, bearing interest at LIBOR plus 3.75% at December 31, 2019
Line of Credit Facility [Line Items]
Basis spread			3.75%
Credit Facility | LIBOR | Multi-currency Revolver of $126 million maturing in November 2022, $48 million available, bearing interest at LIBOR plus 3.75% at December 31, 2019
Line of Credit Facility [Line Items]
Basis spread			3.75%
Credit Facility | Minimum | Revolving Credit Facility
Line of Credit Facility [Line Items]
Required availability on facility			$ 80,000,000
Credit Facility | Minimum | Base Rate
Line of Credit Facility [Line Items]
Basis spread	2.00%
Credit Facility | Minimum | LIBOR
Line of Credit Facility [Line Items]
Basis spread	3.00%
Credit Facility | Maximum | Revolving Credit Facility
Line of Credit Facility [Line Items]
Required availability on facility			$ 90,000,000
Credit Facility | Maximum | Base Rate
Line of Credit Facility [Line Items]
Basis spread	3.00%
Credit Facility | Maximum | LIBOR
Line of Credit Facility [Line Items]
Basis spread	4.00%
Before December 31, 2021 | Credit Facility
Line of Credit Facility [Line Items]
Net leverage ratio (no greater than)			5.60
Interest coverage ratio (no less than)			1.65
After December 31, 2021 | Credit Facility
Line of Credit Facility [Line Items]
Net leverage ratio (no greater than)			3.00
Interest coverage ratio (no less than)			3.00