Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 1,539,063	$ 935,895
Investments	1,019,462	703,052
Receivables	596,456	298,935
Income tax refundable	0	32,742
Deferred income taxes	39,532	26,556
Prepaid expenses and other current assets	50,884	42,484
Total current assets	3,245,397	2,039,664
Property, equipment, and capitalized software, net	340,778	292,083
Deferred contract costs	53,675	45,675
Intangible assets, net	89,273	98,871
Goodwill	271,964	230,738
Restricted investments	102,479	63,093
Derivative asset	329,323	186,351
Other assets	44,326	46,462
Total assets	4,477,215	3,002,937
Current liabilities:
Medical claims and benefits payable	1,200,522	669,787
Accounts payable and accrued liabilities	241,654	263,043
Amounts due government agencies	527,193	56,922
Deferred revenue	196,076	122,216
Income taxes payable	8,987	0
Current maturities of long-term debt	341	182,008
Total current liabilities	2,174,773	1,293,976
Convertible senior notes	704,097	416,368
Lease financing obligations	160,710	159,394
Lease financing obligations - related party	40,241	27,092
Deferred income taxes	24,271	580
Derivative liability	329,194	186,239
Other long-term liabilities	33,487	26,351
Total liabilities	3,466,773	2,110,000
Stockholders’ equity:
Common stock, $0.001 par value; 150,000 shares authorized; outstanding: 49,727 shares at December 31, 2014 and 45,871 shares at December 31,2013	50	46
Preferred stock, $0.001 par value; 20,000 shares authorized, no shares issued and outstanding	0	0
Additional paid-in capital	396,059	340,848
Accumulated other comprehensive loss	(1,019)	(1,086)
Retained earnings	615,352	553,129
Total stockholders’ equity	1,010,442	892,937
Total liabilities and stockholders' equity	$ 4,477,215	$ 3,002,937