Income Taxes Carryforwards (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2010	Dec. 31, 2012 Internal Revenue Service (IRS) [Member]	Mar. 31, 2013 Subsequent Event [Member]
Operating Loss Carryforwards [Line Items]
Federal Net Operating Loss Carryforwards to Expire in 2030			$ 223.6
Federal Tax Credit Carryforwards that Expire Beginning in 2023			25.2
Deferred Tax Assets, Operating Loss Carryforwards, State and Local, Decrease	$ 0.7	$ 2.6		$ 1.5