Health Care, Pension and Other Benefits - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Domestic pension plan settlement expense				$ 32,410
Shares of company stock included in transfer				$ 131,781
Defined Benefit Pension Plans | Terminated Plan
Defined Benefit Plan Disclosure [Line Items]
Domestic pension plan settlement expense		$ 32,400
Defined Benefit Pension Plans | Replacement Plan
Defined Benefit Plan Disclosure [Line Items]
Surplus transferred upon termination and replacement		201,800
Shares of company stock included in transfer		$ 131,800
Shares of company stock included in transfer (in shares)		300,000