Commitments and Contingencies, Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Leases [Abstract]
Total expenses under operating lease obligations	$ 1.2	$ 1.1	$ 1.3
Office Space and Other Equipment
Operating Leases, Future Minimum Payments Due [Abstract]
2017	1.0
2018	1.0
2019	1.0
2020	0.9
2021	0.8
Thereafter	5.3
Total	$ 10.0