CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash flows from operating activities:
Net income	$ 114,771	$ 109,395
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	18,422	17,615
Loss on disposal or abandonment of property, equipment and software	320	24
Deferred tax benefit	(144)	(1,972)
Compensation expense related to share-based payments	10,757	9,571
Convertible debt non-cash interest	5,682	5,323
Gain on sale of intangible assets		(4,000)
Other	7,263	4,189
Changes in assets and liabilities (decreasing) increasing cash flows from operations:
Premium receivables	(31,616)	(10,140)
Prepaid expenses, provider and other receivables and other current assets	(28,722)	(6,138)
Other assets	(2,106)	(55)
Claims payable	8,833	(3,433)
Accounts payable, accrued expenses, contractual refunds payable and other current liabilities	10,653	41,371
Unearned revenue	1,146	(50,474)
Other long-term liabilities	(606)	(1,714)
Net cash provided by operating activities	114,653	109,562
Cash flows from investing activities:
Proceeds from sale of trading securities		8,992
Proceeds from sale of available-for-sale securities	464,366	416,066
Purchase of available-for-sale securities	(721,853)	(575,966)
Proceeds from redemption of investments on deposit for licensure	68,374	36,007
Purchase of investments on deposit for licensure	(78,606)	(48,523)
Purchase of property, equipment and software	(20,170)	(13,508)
Proceeds from sale of intangible assets		4,000
Purchase of contract rights and related assets		(13,420)
Net cash used in investing activities	(287,889)	(186,352)
Cash flows from financing activities:
Net increase in bank overdrafts	16,262	13,361
Customer funds administered	3,078	1,404
Proceeds from exercise of stock options and employee stock purchases	40,020	9,761
Repurchase of common stock shares	(79,997)	(43,676)
Tax benefit (expense) related to share-based payments	12,698	(142)
Net cash used in financing activities	(7,939)	(19,292)
Net decrease in cash and cash equivalents	(181,175)	(96,082)
Cash and cash equivalents at beginning of period	763,946	505,915
Cash and cash equivalents at end of period	582,771	409,833
Supplemental disclosures of non-cash information:
Employee stock relinquished for payment of taxes	(3,621)	(1,714)
Unrealized gain on available-for-sale securities, net of tax	5,355	944
Auction rate securities pending settlement		$ 3,008