CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common shares, par value (in dollars per share)	$ 1	$ 1
Common shares, shares authorized (in shares)	1,400,000,000	1,400,000,000
Common shares, shares issued (in shares)	275,600,000	293,900,000
Common shares, shares outstanding (in shares)	275,600,000	293,900,000
Preferred shares, shares authorized (in shares)	1,000,000	1,000,000
Preferred shares, shares issued (in shares)	0	0
Preferred shares, shares outstanding (in shares)	0	0