Employee Benefit Plans (Net periodic benefit costs) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 317	$ 321
Interest cost	5,638	6,088
Recognized actuarial loss	(70)	0
Expected return on plan assets	(5,446)	(6,241)
Net periodic benefit cost	$ 439	$ 168