Rate and Regulatory Matters (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Regulatory Assets	$ 34,386	$ 72,831
Postretirement Benefits
Regulatory Assets	20,826	53,142
Remaining recovery period	Various
Income Taxes
Regulatory Assets	12,207	17,866
Remaining recovery period	Various
Rate Cases, Storm Costs, Tank Painting, and Other
Regulatory Assets	$ 1,353	$ 1,823
Remaining recovery period	2-9 years