Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net earnings	$ 135,369	$ 170,719
Adjustments to earnings:
Depreciation and amortization	37,631	36,303
Amortization of stock compensation	5,972	9,014
RADV release	0	(132,977)
RADV release - deferred tax adjustment	0	50,531
Changes in assets and liabilities:
Accounts receivable, net	11,268	39,538
Other receivables, net	(52,403)	(84,455)
Medical liabilities	57,643	101,984
Accounts payable and other accrued liabilities	20,252	(145,907)
Deferred revenue	13,018	343,163
Other operating activities	(6,525)	32,602
Net cash from operating activities	222,225	420,515
Cash flows from investing activities:
Capital expenditures, net	(15,871)	(23,517)
Proceeds from sales of investments	282,922	249,120
Proceeds from maturities of investments	67,125	122,567
Purchases of investments	(411,368)	(345,530)
Payments for acquisitions, net of cash acquired	0	(46,980)
Net cash from investing activities	(77,192)	(44,340)
Cash flows from financing activities:
Proceeds from issuance of stock	4,397	25,404
Payments for repurchase of stock	(664)	(4,564)
Repayment of debt	0	(233,903)
Excess tax benefit from stock compensation	565	2,868
Payments for cash dividends	(16,815)	0
Net cash from financing activities	(12,517)	(210,195)
Net change in cash and cash equivalents	132,516	165,980
Cash and cash equivalents at beginning of period	1,399,162	1,579,003
Cash and cash equivalents at end of period	$ 1,531,678	$ 1,744,983