STOCKHOLDERS' EQUITY - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands				6 Months Ended	9 Months Ended
	Aug. 28, 2017	Feb. 22, 2017	Feb. 16, 2017	Aug. 28, 2017	Sep. 30, 2017	Sep. 30, 2016	Nov. 03, 2017	Feb. 14, 2017	Dec. 31, 2016
Equity, Class of Treasury Stock [Line Items]
Share repurchase authorization								$ 2,250,000,000	$ 2,000,000,000
Remaining authorized amount									1,040,000,000
Common shares acquired in connection with employee stock plans (in shares)					370	450
Common shares acquired in connection with employee stock plans, amount					$ 79,000,000	$ 75,000,000
Treasury stock reissued (in shares)					1,400
Treasury stock reissued					$ 99,000,000
Accumulated other comprehensive gain (loss)					12,000,000				(66,000,000)
Net unrealized gains on our investment securities
Equity, Class of Treasury Stock [Line Items]
Accumulated other comprehensive gain (loss)					107,000,000				(17,000,000)
Additional liability that would exist on closed block of long-term care policies assuming unrealized gains on investments backing such products were realized and reinvested at current yields
Equity, Class of Treasury Stock [Line Items]
Accumulated other comprehensive gain (loss)					$ 95,000,000				$ 49,000,000
Accelerated Share Repurchase Agreement
Equity, Class of Treasury Stock [Line Items]
Value of shares repurchased	$ 300,000,000	$ 1,200,000,000	$ 1,500,000,000
Share repurchase payment		$ 1,500,000,000
Shares repurchased in open market (in shares)	840	5,830		6,670
Average cost per share (in dollars per share)				$ 224.81
Decrease in capital in excess of par value		$ 300,000,000
Subsequent Event | February 14, 2017 Share Repurchase Authorization
Equity, Class of Treasury Stock [Line Items]
Remaining authorized amount							$ 239,000,000