Pension, Savings, And Other Employee Benefits - Schedule Of Components Of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8	$ 10
Interest cost	7,575	6,986
Expected return on plan assets	(9,173)	(8,225)
Actuarial (gain)/loss	2,435	2,956
Net periodic benefit cost/(credit)	845	1,727
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	24	33
Interest cost	351	327
Expected return on plan assets	(269)	(269)
Actuarial (gain)/loss	(117)	(91)
Net periodic benefit cost/(credit)	$ (11)	$ 0