Employee Benefit Plans (Narrative) (Details) - 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]
Annual benefits paid to retired participants			$ 300
Other Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benfit plan, cash contributions	$ 200	$ 200	400	$ 200
Expected cash contributions	1,200		1,200
Pension Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benfit plan, cash contributions	800	$ 1,000	1,300	$ 1,500
Expected cash contributions	$ 2,000		$ 2,000