Employee Benefit Plans Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Retirement plan and pension plan, total	$ 11,917	$ 12,289	$ 11,728
Amount to be amortized from accumulated other comprehensive income (loss) in next twelve months	2,300
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Pension Plan	(502)	(497)	(466)
Other Postretirement Benefit Plan | 401k Plan
Defined Benefit Plan Disclosure [Line Items]
401(k) Retirement Plan	$ 8,482	8,121	7,418
Maximum percentage of eligible employee’s covered compensation	5.00%
Percentage of plan vested	100.00%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension Plan	$ 3,435	$ 4,168	$ 4,310