Employee Benefit Plans (Change in Accumulated Other Comprehensive Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial loss	$ 1,247	$ 3,575
Amortization of unrecognized net loss	(505)	(365)	(425)
Amortization of net actuarial loss	505	365	425
Total recognized in accumulated other comprehensive loss (gain)	742	3,210
Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial loss	6,054	1,032
Amortization of unrecognized net loss	(374)	(289)	(182)
Amortization of net actuarial loss	374	289	182
Amortization of prior service cost	(241)	(241)	(241)
Total recognized in accumulated other comprehensive loss (gain)	$ 5,439	$ 502