Income Taxes (Tax Credit Carryforwards) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Federal [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforward	$ 4.9
Tax credit carryforward with expiration date	4.5
Tax credit carryforward with no expiration date	0.4
State [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforward	$ 3.5