Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
ASSETS
Cash and cash equivalents	$ 230,335	$ 340,110
Investments-available-for-sale (amortized cost: 2013-$1,734,953, 2012-$1,753,931)	1,767,156	1,812,512
Premiums receivable, net of allowance for doubtful accounts (2013-$1,105, 2012-$668)	519,287	373,269
Amounts receivable under government contracts	207,891	228,316
Other receivables	66,520	113,875
Deferred taxes	62,027	51,086
Other assets	120,233	130,796
Total current assets	2,973,449	3,049,964
Property and equipment, net	188,038	183,793
Goodwill	565,886	565,886
Other intangible assets, net	16,414	17,271
Deferred taxes	8,006	13,583
Investments-available-for-sale-noncurrent (amortized cost: 2013-$0, 2012-$0)	0	0
Other noncurrent assets	123,514	103,893
Total Assets	3,875,307	3,934,390
LIABILITIES AND STOCKHOLDERS' EQUITY
Reserves for claims and other settlements	1,097,744	1,037,973
Health care and other costs payable under government contracts	77,380	75,649
Unearned premiums	139,584	151,048
Accounts payable and other liabilities	302,171	373,426
Total current liabilities	1,616,879	1,638,096
Senior notes payable	399,146	399,095
Borrowings under revolving credit facility	100,000	100,000
Other noncurrent liabilities	230,666	240,169
Total Liabilities	2,346,691	2,377,360
Commitments and contingencies
Stockholders' Equity:
Preferred stock ($0.001 par value, 10,000 shares authorized, none issued and outstanding)	0	0
Common stock ($0.001 par value, 350,000 shares authorized; issued 2013-149,973 shares; 2012-148,727 shares )	150	149
Additional paid-in capital	1,352,458	1,329,000
Treasury common stock, at cost (2013-70,646 shares of common stock; 2012-67,426 shares of common stock)	(2,177,840)	(2,092,625)
Retained earnings	2,343,572	2,293,522
Accumulated other comprehensive income	10,276	26,984
Total Stockholders' Equity	1,528,616	1,557,030
Total Liabilities and Stockholders' Equity	$ 3,875,307	$ 3,934,390