Pension Plans and Other Postretirement Benefits (Details 2) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Defined Benefit Plan [Member]
Contributions made and expected full year contributions for the Company's plans
Minimum funding requirement for 2012	$ 1,000
Contributions made in the nine months ended September 30, 2012	2,534
Expected contributions (approximations) for the year ended December 31, 2012 as of the time of:
This Form 10-Q (1)	2,550
The 2011 Form 10-K (2)	2,300
Supplemental Defined Benefit Plans [Member]
Contributions made and expected full year contributions for the Company's plans
Contributions made in the nine months ended September 30, 2012	985
Expected contributions (approximations) for the year ended December 31, 2012 as of the time of:
This Form 10-Q (1)	1,300
The 2011 Form 10-K (2)	1,300
Other Postretirement Benefit Plans [Member]
Contributions made and expected full year contributions for the Company's plans
Contributions made in the nine months ended September 30, 2012	363
Expected contributions (approximations) for the year ended December 31, 2012 as of the time of:
This Form 10-Q (1)	519
The 2011 Form 10-K (2)	$ 519