Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2017	Dec. 31, 2016	[1]
Statement of Financial Position [Abstract]
Preferred stock, no par value
Preferred stock, authorized	1,000,000	1,000,000
Preferred stock, issued	0	0
Common stock, par value	$ 1	$ 1
Common stock, authorized	1,200,000,000	1,200,000,000
Common stock, issued	351,300,000	350,700,000

[1] The December 31, 2016 consolidated balance sheet has been derived from audited financial statements.