Statement of Consolidated Stockholders' Equity (Parenthetical) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2019 USD ($) $ / shares
Statement of Financial Position [Abstract]
Weighted-average repurchase price (dollars per share)		$ 96.18
Repurchase amount remaining available | $	$ 105.6	$ 105.6
Dividends declared per common share (in dollars per share)	$ 0.60	$ 2.40