Employee Benefit Plans and Other Postretirement Benefits - Schedule Of Pension Plans With PBO And ABO In Excess Of Fair value Of Plan Assets (Details) - Pension and SERPA Benefits - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
PBO	$ 58,804	$ 1,984,708
Fair value of plan assets	0	1,874,618
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
ABO	44,232	40,085
Fair value of plan assets	$ 0	$ 0