Capital Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended			19 Months Ended
	Jan. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options and restricted stock, anti-dilutive		4,700,000	7,000,000	4,500,000
Common stock share purchase, shares		40,000,000
Common stock share repurchase, shares		0	0	20,950,729	32,200,000
Common stock share repurchase, per share					$ 88.96
Common stock dividends (in USD per share)		$ 1.00	$ 1	$ 0.95
Shares authorized and available for grant		22,900,000
Compensation expense		$ 131	$ 100	$ 148
Stock-based compensation expenses, after tax		$ 93	65	95
Exercised, Shares		0
Intrinsic value of options exercised			3	13
Stock-based compensation capitalized		$ 40	53	62
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation cost related to non-vested awards not yet recognized		6
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		113	90	111
Stock-based compensation expenses, after tax		73	$ 58	$ 72
Total compensation cost related to non-vested awards not yet recognized		$ 233
Granted, Shares		4,049,023	2,976,562	3,046,744
Weighted average grant date fair value per share (in USD per share)		$ 47.37	$ 61.65	$ 86.87
Stock-based compensation capitalized		$ 35	$ 48	$ 47
Weighted-average remaining life of unvested restricted stock units		1 year 3 months 6 days
Unvested restricted stock units		6,061,803
Total fair value of restricted stock awards vested		$ 151	$ 149	$ 138
Subsequent Event [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period in which stock options become exercisable	3 years
Total compensation cost related to non-vested awards not yet recognized	$ 9
Options Issued	489,773
Subsequent Event [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period in which stock options become exercisable	3 years
Total compensation cost related to non-vested awards not yet recognized	$ 118
Options Issued	1,866,606
Weighted average grant date fair value per share (in USD per share)	$ 63.25
Prior to 2016 [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period in which stock options become exercisable		4 years
Period in which stock options expires after grant date		10 years
In or After 2016 [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period in which stock options become exercisable		3 years
Period in which stock options expires after grant date		10 years