Commitments and Contingencies Commitments and Contingencies (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Total costs to remediate IRC Section 7702 issue		$ 11.4
Toll charges and fees to remediate IRC Section 7702 issue		10.1
Cost of claim and reserve liabilities to remediate IRC Section 7702 issue		$ 1.3
Toll Charges and Fees to Remediate IRC Section 72(s)	$ 2.5
IRC Section 7702 remediation costs [Member]
Loss Contingencies [Line Items]
Loss Contingency, Range of Possible Loss, Minimum	0.5
Loss Contingency, Range of Possible Loss, Maximum	1.3
Minimum [Member]
Loss Contingencies [Line Items]
Cost Range to Remediate IRC Section 7702 and 72(s) Issue	13.9
Maximum [Member]
Loss Contingencies [Line Items]
Cost Range to Remediate IRC Section 7702 and 72(s) Issue	$ 46.6