Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Net premiums, principally supplemental health insurance		$ 4,706	$ 4,665	$ 9,450	$ 9,303
Net investment income		862	802	1,699	1,596
Realized investment gains (losses):
Other-than-temporary impairment losses realized		(5)		(12)
Other-than-temporary impairment losses			(9)		(19)
Other gains (losses)	[1]	8	(47)	(119)	(177)
Total realized investment gains (losses)		3	(56)	(131)	(196)
Other income (loss)		18	17	36	34
Total revenues		5,589	5,428	11,054	10,737
Benefits and expenses:
Benefits and claims, net		3,031	3,039	6,073	6,091
Acquisition and operating expenses:
Amortization of deferred policy acquisition costs		303	283	617	577
Insurance commissions		338	335	676	664
Insurance and other expenses		732	665	1,463	1,339
Interest expense		54	61	111	122
Total acquisition and operating expenses		1,427	1,344	2,867	2,702
Total benefits and expenses		4,458	4,383	8,940	8,793
Earnings before income taxes		1,131	1,045	2,114	1,944
Income taxes		299	332	564	639
Net earnings		$ 832	$ 713	$ 1,550	$ 1,305
Net earnings per share:
Basic (in dollars per share)		$ 1.08	$ 0.90	$ 2.00	$ 1.64
Diluted (in dollars per share)		$ 1.07	$ 0.89	$ 1.98	$ 1.62
Weighted-average outstanding common shares used in computing earnings per share (In thousands):
Basic (in shares)		772,949	792,865	775,734	797,536
Diluted (in shares)		777,807	798,695	780,814	803,391
Cash dividends per share		$ 0.26	$ 0.22	$ 0.52	$ 0.43

[1] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.