Employee Benefit Plans Amounts Recognized Accumlated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Prior year accumulated other comprehensive income	$ (40,222)	$ (29,822)
Amortization of prior service costs	2,018	2,018
Amortization of gain (loss)	1,463	701
Net (loss) gain arising during the year	(1,087)	(13,119)
Current year accumulated other comprehensive (loss) income	(37,828)	(40,222)
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior year accumulated other comprehensive income	(40,717)	(30,210)
Amortization of prior service costs	2,018	2,018
Amortization of gain (loss)	1,584	789
Net (loss) gain arising during the year	(531)	(13,314)
Current year accumulated other comprehensive (loss) income	(37,646)	(40,717)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior year accumulated other comprehensive income	495	388
Amortization of prior service costs	0	0
Amortization of gain (loss)	(121)	(88)
Net (loss) gain arising during the year	(556)	195
Current year accumulated other comprehensive (loss) income	$ (182)	$ 495