Benefit Plans (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	4.00%
Benefit Plan Expense, Defined Benefit Plans and Defined Contribution Plans	$ 10,859	$ 13,505	$ 13,849