Commitments and Contingencies Operating Leases Disclosures - ASC 842 (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Leases [Abstract]
Earnest Money Deposits and Pre-acquisition Costs Written-Off	$ 0.5	$ 0.1
Short-term Lease, Cost	0.1
Operating Lease, Expense	0.3
Operating Lease, Payments	$ 0.3
Operating Lease, Weighted Average Remaining Lease Term	3 years 11 months
Operating Lease, Weighted Average Discount Rate, Percent	5.25%