Legal Proceedings (Details) (Class Action Lawsuit, USD $) In Millions, unless otherwise specified	Jun. 19, 2012 Approved by Court on June 19, 2012 Securities Class Action Complaint	Sep. 30, 2012 Pending Litigation ERISA Class Action Suit
Loss Contingencies [Line Items]
Liability Insurers Settlement Fund	$ 25.0	$ 2.1