Income Taxes (Tax Credit Carryforwards) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Federal [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforward	$ 6.6
Tax credit carryforward with expiration date	6.1
Tax dredit carryforward with no expiration date	0.5
State [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforward	5.5
Tax dredit carryforward with no expiration date	$ 5.5