Income Taxes (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Alternative minimum tax credit
Net operating loss carryforward
Alternative minimum tax credit that can be carried forward	$ 1.4
Federal
Net operating loss carryforward
Net operating loss carryforward	59.2
Federal | 2030
Net operating loss carryforward
Net operating loss carryforward	23.1
Federal | 2031
Net operating loss carryforward
Net operating loss carryforward	29.5
Federal | 2032
Net operating loss carryforward
Net operating loss carryforward	6.6
State
Net operating loss carryforward
Net operating loss carryforward	107.2
State | 2024
Net operating loss carryforward
Net operating loss carryforward	29.2
State | 2025
Net operating loss carryforward
Net operating loss carryforward	$ 78.0