Condensed Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 1,519	$ 1,306
Investment securities	7,556	8,001
Receivables, less allowance for doubtful accounts of $109 in 2013 and $94 in 2012	1,593	733
Other current assets	1,960	1,670
Total current assets	12,628	11,710
Property and equipment, net	1,133	1,098
Long-term investment securities	1,770	1,846
Goodwill	3,638	3,640
Other long-term assets	1,679	1,685
Total assets	20,848	19,979
Current liabilities:
Benefits payable	4,157	3,779
Trade accounts payable and accrued expenses	2,174	2,042
Book overdraft	246	324
Unearned revenues	193	230
Total current liabilities	6,770	6,375
Long-term debt	2,606	2,611
Future policy benefits payable	1,810	1,858
Other long-term liabilities	327	288
Total liabilities	11,513	11,132
Commitments and contingencies
Stockholders' equity:
Preferred stock, $1 par; 10,000,000 shares authorized; none issued	0	0
Common stock, $0.16 2/3 par; 300,000,000 shares authorized; 195,678,752 shares issued at June 30, 2013 and 194,470,820 shares issued at December 31, 2012	32	32
Capital in excess of par value	2,190	2,101
Retained earnings	8,688	7,881
Accumulated other comprehensive income	209	386
Treasury stock, at cost, 39,215,632 shares at June 30, 2013 and 36,138,955 shares at December 31, 2012	(1,784)	(1,553)
Total stockholders' equity	9,335	8,847
Total liabilities and stockholders' equity	$ 20,848	$ 19,979