Commitments and Contingencies (Narrative or Textuals) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Commitments And Contingencies [Line Items]
Pretax cat loss after reinsurance	$ 10.5	$ 9.5
Longest Indemnification Expiration Date	2025
Remaining Commitment of Middle Market Senior Loan Program	$ 147.0
Original Commitment of Middle Market Senior Loan Program	$ 150.0