Statements of Consolidated Comprehensive Income Other Comprehensive Income, Deferred Tax (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Other Comprehensive Income, Deferred Tax [Abstract]
Amortization of net actuarial loss included in net periodic benefit expense or income, tax	$ 1,285	$ 794
Amortization of prior service credit included in net periodic benefit expense or income, tax	$ 80	$ 122