Income Taxes (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Examination [Line Items]
Total income tax payments	$ 5,950	$ 1,950	$ 8,400
Statutory rate	35.00%
State franchise taxes	1,295	1,265	1,151
Vermont [Member]
Income Tax Examination [Line Items]
State franchise taxes	$ 1,200	$ 1,180	$ 1,070