Significant Accounting Policies (Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis) (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Assets [Abstract]
Rabbi Trust Assets		$ 86,000,000
Total Assets	35,473,000	85,741,000
Liabilities [Abstract]
Total Liabilities		(4,290,000)
Fair Value, Inputs, Level 1 [Member]
Assets [Abstract]
Total Assets	0	85,741,000
Liabilities [Abstract]
Total Liabilities		0
Fair Value, Inputs, Level 2 [Member]
Assets [Abstract]
Total Assets	35,473,000	0
Liabilities [Abstract]
Total Liabilities		(4,290,000)
Fair Value, Inputs, Level 3 [Member]
Assets [Abstract]
Total Assets	0	0
Liabilities [Abstract]
Total Liabilities		$ 0