Benefit Plans (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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	$ 13,849	$ 10,371	$ 8,929