Pension And Other Retirement Plans Net Periodic Benefit Cost For Pension Benefit Plan (Details) - Pension Plan - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 174	$ 198	$ 467	$ 384
Interest cost	17,829	19,528	35,569	39,097
Expected return on plans’ assets	(24,823)	(25,236)	(49,641)	(50,563)
Recognized actuarial loss	8	0	8	0
Amortization of prior service costs	35	35	70	58
Net periodic benefit credit	$ (6,777)	$ (5,475)	$ (13,527)	$ (11,024)