Employee and Retiree Benefit Plans - Narrative (Details) $ in Thousands	12 Months Ended					120 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Future annual rate of increase in cost of health care for 2016 to measure postretirement benefit obligations		6.50%
Ultimate rate of health care cost in 2028 and thereafter		4.50%
Plan asset, maximum investment in any one issuer		10.00%
Equity securities minimum market capitalization		$ 100,000
Fixed income portfolio, maximum average maturity years		11 years
Weighted average expected return on plan asset			5.51%
Basis used to determine expected return on plan asset, average expected investment expenses			0.60%
Perentage return on plan assets over the last ten years						7.56%
Number of investments in hedge funds and other alternative investments		3
Defined benefit plan, percentage of employer's matching contribution		6.00%
Thrift plan expense			$ 8,400	$ 5,200	$ 7,800
Third investment
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Domestic plan, investment lock up period		2 years
Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average expected return on plan asset			6.30%
Defined Benefit Plan, Fixed Income Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average expected return on plan asset			3.95%
Defined Benefit Plan, Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Domestic plan, investment notice period		10 days
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to benefit plans		$ 25,915	$ 24,357
Weighted average expected return on plan asset			5.05%	5.37%
Pension Benefits | United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to benefit plans		25,700
Pension Benefits | Foreign Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to benefit plans		200
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to benefit plans		2,333	$ 3,044
Weighted average expected return on plan asset			0.00%	0.00%
Other Postretirement Benefits | United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to benefit plans		$ 2,300
Subsequent Event | Pension Benefits | United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to benefit plans	$ 30,600
Subsequent Event | Pension Benefits | Foreign Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to benefit plans	600
Subsequent Event | Other Postretirement Benefits | United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to benefit plans	$ 5,200
Second Investment
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Domestic plan, investment notice period		90 days
Third investment
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Domestic plan, investment notice period		95 days