Net Income Per Share (TEU) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		9 Months Ended
	Sep. 17, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Tangible equity units issued	16,500,000
Tangible equity units proceeds	$ 800.2
Price for basic share (usd per share)	$ 0.3134
Price for shares diluted (usd per share)	$ 0.3839
Difference amount between basic and diluted net income per share			$ 0.01
Net income allocated to PRS		$ 0.2	$ 0.1	$ 0.5	$ 0.6