Earnings Per Share - Calculation of Average Share Outstanding (Details) - $ / shares shares in Millions		12 Months Ended
	Oct. 15, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average exercise price of options (usd per share)		$ 35.75	$ 26.79	$ 33.32
Mandatory convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of anti-dilutive securities (in shares)				39
Convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of anti-dilutive securities (in shares)	15	0	0	14
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of anti-dilutive securities (in shares)		1	9	11
Stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of anti-dilutive securities (in shares)		0	0	7