Employee Benefit Plans Employee Benefit Plans and Components of Net Periodic Postretirement Benefit Cost (Benefit) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 699	$ 608	$ 539
Interest cost	6,327	6,832	7,393
Expected return on assets	(9,278)	(9,855)	(10,054)
Amortization of prior service cost	322	324	324
Amortization of actuarial loss	1,942	594	229
Net periodic pension cost (benefit)	12	(1,497)	(1,569)
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	153	161	164
Interest cost	148	170	222
Amortization of prior service cost	0	0	0
Amortization of actuarial loss	(23)	0	0
Net periodic pension cost (benefit)	$ 278	$ 331	$ 386