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	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary of net periodic benefit cost
Interest cost on projected benefit obligation	$ 4,055	$ 4,144	$ 3,710
Return on plan assets	(5,021)	(4,797)	(4,509)
Recognized net actuarial loss	1,869	4,385	6,330
Net periodic benefit cost	$ 903	$ 3,732	$ 5,531
Actuarial Assumptions Used to Determine Net Cost
Discount rate (as a percent)	3.75%	4.47%	3.58%
Expected return on assets (as a percent)	6.50%	6.75%	6.75%