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 income	$ 28,058	$ 20,790
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	16,170	14,781
Non-cash interest expense	184	177
Non-cash stock compensation expense	5,638	5,102
Non-cash income tax expense	(630)	2,696
Non-cash amortization on investments	2,508	1,760
Cash flows from changes in assets and liabilities, net of effects from acquisitions of businesses:
Restricted cash	4,764	852
Accounts receivable, net	(8,359)	(12,106)
Pharmaceutical inventory	(2,004)	(3,502)
Other assets	(2,039)	6,068
Accounts payable and accrued liabilities	(15,285)	(26,724)
Medical claims payable and other medical liabilities	15,752	19,201
Tax contingencies	601	690
Other	521	(216)
Net cash provided by operating activities	45,879	29,569
Cash flows from investing activities:
Capital expenditures	(11,382)	(14,505)
Purchase of investments	(66,596)	(61,977)
Maturity of investments	47,647	97,168
Net cash provided by (used in) investing activities	(30,331)	20,686
Cash flows from financing activities:
Payments to acquire treasury stock	(24,830)
Proceeds from exercise of stock options and warrants	9,675	2,197
Payments on capital lease obligations	(414)
Other	(1,022)	(743)
Net cash provided by (used in) financing activities	(16,591)	1,454
Net increase (decrease) in cash and cash equivalents	(1,043)	51,709
Cash and cash equivalents at beginning of period	189,464	119,862
Cash and cash equivalents at end of period	188,421	171,571
Non-cash investing activities:
Property and equipment acquired under capital leases	$ 28,836