Taxes Other Than Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Taxes, Other	$ 160,627	$ 162,426	$ 174,392
Production Taxes [Member]
Taxes, Other	84,984	77,629	99,442
Real Estate Properties [Domain]
Taxes, Other	36,338	43,679	35,495
Payroll Taxes [Member]
Taxes, Other	32,779	32,478	33,155
Capital Stock and Franchise Tax [Member]
Taxes, Other	6,833	9,013	3,670
Virginia employment enhancement tax credit [Member]
Taxes, Other	(4,683)	(4,311)	(6,109)
Other taxes [Member]
Taxes, Other	$ 4,376	$ 3,938	$ 8,739