Employee and Retiree Benefit Plans - Fair Value Measurements of Retirement Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	$ 547,484	$ 487,094
Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	102,651	86,885
Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	333,011	365,154
Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	111,586	35,055
United States
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	349,519	316,543
United States | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	102,651	86,885
United States | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	170,943	194,603
United States | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	75,925	35,055
United States | U.S. core equity
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	63,169	62,105
United States | U.S. core equity | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	63,169	62,105
United States | U.S. core equity | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | U.S. core equity | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | U.S. small/midcap
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	26,062	19,436
United States | U.S. small/midcap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	26,062	19,436
United States | U.S. small/midcap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | U.S. small/midcap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | Hedged funds and other alternative strategies
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	58,864	45,844
United States | Hedged funds and other alternative strategies | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | Hedged funds and other alternative strategies | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	10,789
United States | Hedged funds and other alternative strategies | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	58,864	35,055
United States | International commingled trust fund
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	73,783	63,089
United States | International commingled trust fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	924	0
United States | International commingled trust fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	55,798	63,089
United States | International commingled trust fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	17,061	0
United States | Emerging market commingled equity fund
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	25,911	15,355
United States | Emerging market commingled equity fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	8,011	0
United States | Emerging market commingled equity fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	17,900	15,355
United States | Emerging market commingled equity fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | U.S. fixed income
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	88,525	87,526
United States | U.S. fixed income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | U.S. fixed income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	88,525	87,526
United States | U.S. fixed income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | International commingled trust fund
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	8,720	13,274
United States | International commingled trust fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | International commingled trust fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	8,720	13,274
United States | International commingled trust fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | Emerging market mutual fund
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets		4,570
United States | Emerging market mutual fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets		0
United States | Emerging market mutual fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets		4,570
United States | Emerging market mutual fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets		0
United States | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	4,485	5,344
United States | Cash and equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	4,485	5,344
United States | Cash and equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
United States | Cash and equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
Foreign Plans
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	197,965	170,551
Foreign Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
Foreign Plans | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	162,068	170,551
Foreign Plans | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	35,661	0
Foreign Plans | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	4,262	3,207
Foreign Plans | Cash and equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
Foreign Plans | Cash and equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	4,256	3,207
Foreign Plans | Cash and equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
Foreign Plans | Equity securities funds
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	68,878	67,165
Foreign Plans | Equity securities funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
Foreign Plans | Equity securities funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	68,840	67,165
Foreign Plans | Equity securities funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
Foreign Plans | Fixed income securities funds
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	46,582	89,417
Foreign Plans | Fixed income securities funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
Foreign Plans | Fixed income securities funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	46,390	89,417
Foreign Plans | Fixed income securities funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
Foreign Plans | Diversified pooled fund
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	42,582	10,762
Foreign Plans | Diversified pooled fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	0
Foreign Plans | Diversified pooled fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	42,582	10,762
Foreign Plans | Diversified pooled fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0	$ 0
Foreign Plans | Other
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	35,661
Foreign Plans | Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0
Foreign Plans | Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	0
Foreign Plans | Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Retirement plan assets	$ 35,661