Pension Plans (Expected Future Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Qualified Pension Plan
Defined Benefit Plan Disclosure [Line Items]
2017	$ 33,480
2018	35,021
2019	36,948
2020	38,533
2021	39,770
2022-2026	$ 218,335
Discount rate	3.98%	4.17%
Discount rate for calculating net periodic benefit cost	4.17%	3.80%
Expected return on plan assets	7.50%	7.50%
SERP
Defined Benefit Plan Disclosure [Line Items]
2017	$ 3,061
2018	519
2019	506
2020	492
2021	2,145
2022-2026	$ 2,423
Discount rate	3.43%	3.47%
Discount rate for calculating net periodic benefit cost	3.47%	3.15%