Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for credit losses	$ 11.5	$ 10.5
Common stock - shares authorized (in shares)	600,000,000	600,000,000
Common stock - shares issued (in shares)	226,738,748	226,641,443