Condensed Consolidated Statements Of Income (Unaudited) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Revenues:        
Premiums $ 13,371 $ 12,987 $ 40,461 $ 39,447
Services 227 246 749 1,143
Investment income 96 130 291 338
Total revenues 13,694 13,363 41,501 40,928
Operating expenses:        
Benefits 10,900 10,896 33,806 33,153
Operating costs 1,759 1,688 5,253 5,450
Depreciation and amortization 86 84 263 267
Total operating expenses 12,745 12,668 39,322 38,870
Income from operations 949 695 2,179 2,058
Gain on sale of business 0 0 0 267
Interest expense 47 47 141 140
Income before income taxes 902 648 2,038 2,185
Provision for income taxes 452 334 1,023 1,010
Net income $ 450 $ 314 $ 1,015 $ 1,175
Basic earnings per common share (in dollars per share) $ 3.01 $ 2.11 $ 6.80 $ 7.85
Diluted earnings per common share (in dollars per share) 2.98 2.09 6.73 7.77
Dividends per common share (in dollars per share) $ 0.29 $ 0.29 $ 0.87 $ 0.86