Employee Benefit Plans (Summary of Net Periodic Benefit Cost and Actuarial Assumptions Used to Determine Net Cost) (Details) (Employee Pension Plans [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Pension Plans [Member]
Summary of net periodic benefit cost
Interest cost on projected benefit obligation	$ 4,144	$ 3,710	$ 4,011
Return on plan assets	(4,797)	(4,509)	(4,783)
Recognized net actuarial loss	4,385	6,330	5,487
Net periodic benefit cost	$ 3,732	$ 5,531	$ 4,715
Actuarial Assumptions Used to Determine Net Cost
Discount rate (as a percent)	4.47%	3.58%	4.10%
Expected return on assets (as a percent)	6.75%	6.75%	7.00%