Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Defined Benefit Postretirement Health Coverage [Member] | Employees Retired before January 1, 1993 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Defined Benefit Plan, Maximum Coverage per Retiree			100.00%
Pension Plans, Defined Benefit [Member]
Components of net periodic benefit costs:
Interest cost	$ 133	$ 152	$ 266	$ 304
Expected return on plan assets	(165)	(196)	(330)	(392)
Defined Benefit Plan, Amortization of Net Gains (Losses)	51	40	103	79
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	0	(353)	0	(353)
Net periodic benefit cost	19	349	39	344
Other Postretirement Benefit Plans, Defined Benefit [Member]
Components of net periodic benefit costs:
Interest cost	1	3	3	5
Defined Benefit Plan, Amortization of Net Gains (Losses)	(4)	1	(4)	(1)
Net periodic benefit cost	$ (3)	$ 4	$ (1)	$ 4
Other Postretirement Benefit Plans, Defined Benefit [Member] | Employees Hired before January 1, 2003 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Defined Benefit Plan, Contribution Per Employee, Coverage Basis, Consecutive Period of Highest Average Monthly Compensation			5 years
Defined Benefit Plan, Contribution Per Employee, Coverage Basis, Lastest Service Period			10 years
Other Postretirement Benefit Plans, Defined Benefit [Member] | Employees Hired on or after January 1, 2003 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Defined Benefit Plan, Annual Contribution Per Employee, Percent			2.00%