Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 148,609	$ 140,715
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and depreciation	15,391	25,804
Asset impairment	1,884	84,690
Share-based compensation expense	21,459	21,809
Deferred income taxes	(755)	(34,755)
Excess tax benefit on share-based compensation	(5,264)	(1,595)
Net realized (gain) loss on investments	(2,087)	(2,582)
Other changes	29,716	23,190
Changes in assets and liabilities, net of effects of acquisitions and dispositions:
Premiums receivable and unearned premiums	144,105	(148,109)
Other current assets, receivables and noncurrent assets	(178,784)	(251,479)
Amounts receivable/payable under government contracts	(15,499)	45,966
Reserves for claims and other settlements	(211,612)	749,232
Accounts payable and other liabilities	622,499	232,777
Net cash provided by operating activities	569,662	885,663
CASH FLOWS FROM INVESTING ACTIVITIES:
Sales of investments	883,428	296,878
Maturities of investments	77,365	64,743
Purchases of investments	(1,424,313)	(361,451)
Purchases of property and equipment	(46,060)	(48,395)
Sales (purchases) of restricted investments and other	(3,464)	2,762
Net cash used in investing activities	(513,044)	(45,463)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercise of stock options and employee stock purchases	18,559	21,417
Excess tax benefit on share-based compensation	5,264	1,595
Repurchases of common stock	(112,139)	(69,686)
Borrowings under financing arrangements	240,000	0
Repayment of borrowings under financing arrangements	(130,000)	0
Net increase (decrease) in checks outstanding, net of deposits	0	0
Customer funds administered	25,473	(112,123)
Net cash provided by (used in) financing activities	47,157	(158,797)
Net increase in cash and cash equivalents	103,775	681,403
Cash and cash equivalents, beginning of period	869,133	433,155
Cash and cash equivalents, end of period	972,908	1,114,558
SUPPLEMENTAL CASH FLOWS DISCLOSURE:
Interest paid	17,246	15,948
Income taxes paid	$ 199,320	$ 63,635