Condensed Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 3,656	$ 1,377
Investment securities	7,889	7,743
Receivables, less allowance for doubtful accounts of $89 in 2012 and $85 in 2011:	1,330	1,034
Other current assets	1,181	1,027
Total current assets	14,056	11,181
Property and equipment, net	939	912
Long-term investment securities	1,704	1,710
Goodwill	2,785	2,740
Other long-term assets	1,216	1,165
Total assets	20,700	17,708
Current liabilities:
Benefits payable	4,108	3,754
Trade accounts payable and accrued expenses	2,123	1,783
Book overdraft	294	306
Unearned revenues	2,298	213
Total current liabilities	8,823	6,056
Long-term debt	1,621	1,659
Future policy benefits payable	1,690	1,663
Other long-term liabilities	332	267
Total liabilities	12,466	9,645
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; 194,119,768 shares issued at March 31, 2012 and 193,230,310 shares issued at December 31, 2011	32	32
Capital in excess of par value	2,043	1,938
Retained earnings	7,032	6,825
Accumulated other comprehensive income	313	303
Treasury stock, at cost, 30,940,528 shares at March 31, 2012 and 29,225,996 shares at December 31, 2011	(1,186)	(1,035)
Total stockholders' equity	8,234	8,063
Total liabilities and stockholders' equity	$ 20,700	$ 17,708