CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 125,261	$ 151,027	$ 129,623
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	71,994	60,488	58,623
Non-cash interest expense	736	728	1,033
Non-cash stock compensation expense	21,252	17,783	17,418
Non-cash income tax expense (benefits)	(1,212)	17,306	8,285
Non-cash amortization on investments	9,107	7,193	12,309
Cash flows from changes in assets and liabilities, net of effects from acquisitions of businesses:
Restricted cash	(2,242)	(40,760)	(69,060)
Accounts receivable, net	(40,804)	(16,411)	(15,609)
Pharmaceutical inventory	(3,882)	(6,160)	(11,657)
Other assets	(9,293)	414	3,804
Accounts payable and accrued liabilities	3,593	(8,321)	(7,251)
Medical claims payable and other medical liabilities	17,866	31,292	(7,905)
Tax contingencies	(22,960)	(35,376)	(9,453)
Deferred credits and other long-term liabilities	10,988	1,901	1,558
Other	2,757	189	285
Net cash provided by operating activities	183,161	181,293	112,003
Cash flows from investing activities:
Capital expenditures	(64,542)	(69,549)	(54,394)
Acquisitions and investments in businesses, net of cash acquired	(107,541)		(376)
Purchase of investments	(323,253)	(321,541)	(259,552)
Maturity of investments	339,428	281,748	330,583
Other		(1,225)
Net cash provided by (used in) investing activities	(155,908)	(110,567)	16,261
Cash flows from financing activities:
Payments on long-term debt and capital lease obligations	(3,001)		(559)
Payments to acquire treasury stock	(60,677)	(21,868)	(407,645)
Proceeds from issuance of equity			20,000
Proceeds from exercise of stock options and warrants	47,529	20,486	41,796
Tax benefit from exercise of stock options and vesting of stock awards	3,212	990	2,038
Other	(593)	(732)	(1,211)
Net cash used in financing activities	(13,530)	(1,124)	(345,581)
Net (decrease) increase in cash and cash equivalents	13,723	69,602	(217,317)
Cash and cash equivalents at beginning of period	189,464	119,862	337,179
Cash and cash equivalents at end of period	$ 203,187	$ 189,464	$ 119,862