Pension, Savings, And Other Employee Benefits - Schedule Of Components Of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7	$ 11	$ 23	$ 31
Interest cost	7,505	6,935	22,655	20,908
Expected return on plan assets	(9,335)	(8,222)	(27,681)	(24,673)
Actuarial (gain)/loss	2,546	3,164	7,416	9,076
Net periodic benefit cost/(credit)	723	1,888	2,413	5,342
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	23	33	71	100
Interest cost	358	328	1,060	982
Expected return on plan assets	(314)	(268)	(852)	(806)
Actuarial (gain)/loss	(112)	(108)	(346)	(290)
Net periodic benefit cost/(credit)	$ (45)	$ (15)	$ (67)	$ (14)