Commitments and Contingencies Rent Expense (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
|
Commitments and Contingencies Disclosure [Abstract] | ||||
Operating Leases, Rent Expense | $ 2.3 | $ 0.2 | $ 5.3 | $ 0.4 |