Fair Value Measurements, Financial Instruments, and Credit Risk - Carrying Values and Approximate Fair Values of Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	May 31, 2018
4.25% Senior Notes | Senior Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt instrument interest rate	4.25%
5.25% Senior Notes | Senior Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt instrument interest rate	5.25%		5.25%
Carrying Value | KFPC Loan Agreement
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	$ 17,853	$ 52,730
Carrying Value | KFPC Revolving Facilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	49,873	37,003
Carrying Value | Finance lease obligations
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	3,163	835
Carrying Value | Euro Tranche | Medium-term Notes | Significant Other Observable Inputs (Level 2)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	96,662	104,159
Carrying Value | 4.25% Senior Notes | Senior Notes | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	400,000	400,000
Carrying Value | 5.25% Senior Notes | Senior Notes | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	329,789	355,366
Carrying Value | ABL Facility | Revolving Credit Facility
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	0	0
Fair Value | KFPC Loan Agreement
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	17,853	52,730
Fair Value | KFPC Revolving Facilities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	49,873	37,003
Fair Value | Finance lease obligations
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	3,163	835
Fair Value | Euro Tranche | Medium-term Notes | Significant Other Observable Inputs (Level 2)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	96,541	103,574
Fair Value | 4.25% Senior Notes | Senior Notes | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	414,152	409,880
Fair Value | 5.25% Senior Notes | Senior Notes | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	339,228	367,886
Fair Value | ABL Facility | Revolving Credit Facility
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt	$ 0	$ 0