Centene (CNC) 10-K 21 Feb 14 2013 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2013	Feb. 14, 2014	Jun. 28, 2013
Document And Entity Information [Abstract]	'	'	'
Entity Registrant Name	'CENTENE CORP	'	'
Entity Central Index Key	'0001071739	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Document Type	'10-K	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Amendment Flag	'false	'	'
Entity Public Float	'	'	$2.90
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Common Stock, Shares Outstanding	'	57,615,380	'

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents of continuing operations	$974,304	$745,933
Cash and cash equivalents of discontinued operations	63,769	98,019
Total cash and cash equivalents	1,038,073	843,952
Premium and related receivables	428,570	251,473
Short-term investments	102,126	138,101
Other current assets	217,661	93,322
Other current assets of discontinued operations	13,743	78,977
Total current assets	1,800,173	1,405,825
Long-term investments	791,900	554,770
Restricted deposits	46,946	34,286
Property, software and equipment, net	395,407	375,893
Goodwill	348,432	256,288
Intangible assets, net	48,780	20,268
Other long-term assets	59,357	64,278
Long term assets of discontinued operations	38,305	62,297
Total assets	3,529,300	2,773,905
Current liabilities:	'	'
Medical claims liability	1,111,709	815,161
Accounts payable and accrued expenses	375,862	219,066
Unearned revenue	38,191	34,597
Current portion of long-term debt	3,065	3,373
Current liabilities of discontinued operations	30,294	157,116
Total current liabilities	1,559,121	1,229,313
Long-term debt	665,697	535,481
Other long-term liabilities	60,015	54,987
Long term liabilities of discontinued operations	1,028	357
Total liabilities	2,285,861	1,820,138
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Common stock, $.001 par value; authorized 100,000,000 shares; 58,673,215 issued and 55,319,239 outstanding at December 31, 2013, and 55,339,160 issued and 52,329,248 outstanding at December 31, 2012	59	55
Additional paid-in capital	594,326	450,856
Accumulated other comprehensive income:	'	'
Unrealized gain on investments, net of tax	-2,620	5,189
Retained earnings	731,919	566,820
Treasury stock, at cost (3,353,976 and 3,009,912 shares, respectively)	-89,643	-69,864
Total Centene stockholders’ equity	1,234,041	953,056
Noncontrolling interest	9,398	711
Total stockholders’ equity	1,243,439	953,767
Total liabilities and stockholders’ equity	$3,529,300	$2,773,905

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Stockholders' equity:	'	'
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	58,673,215	55,339,160
Common stock, shares outstanding	55,319,239	52,329,248
Treasury stock, at cost	3,353,976	3,009,912

Consolidated_Statements_Of_Ope

Consolidated Statements Of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:	'	'	'
Premium	$10,153,460	$7,568,889	$4,948,137
Service	372,580	112,742	103,765
Premium and service revenues	10,526,040	7,681,631	5,051,902
Premium tax	337,289	428,665	159,575
Total revenues	10,863,329	8,110,296	5,211,477
Expenses:	'	'	'
Medical costs	8,994,641	6,781,081	4,191,268
Cost of services	326,924	87,705	78,114
General and administrative expenses	931,137	677,157	577,898
Premium tax expense	333,210	428,354	160,394
Impairment loss	0	28,033	0
Total operating expenses	10,585,912	8,002,330	5,007,674
Earnings from operations	277,417	107,966	203,803
Other income (expense):	'	'	'
Investment and other income	18,457	35,285	13,355
Debt extinguishment costs	0	0	-8,488
Interest expense	-26,957	-20,460	-20,320
Earnings from continuing operations, before income tax expense	268,917	122,791	188,350
Income tax expense	107,080	47,412	70,687
Earnings from continuing operations, net of income tax expense	161,837	75,379	117,663
Net earnings (loss)	165,718	-11,295	108,363
Noncontrolling interest	619	-13,154	-2,855
Net earnings attributable to Centene Corporation	165,099	1,859	111,218
Amounts attributable to Centene Corporation common shareholders:	'	'	'
Earnings from continuing operations, net of income tax expense	161,218	88,533	120,518
Discontinued operations, net of income tax expense (benefit)	3,881	-86,674	-9,300
Net earnings	$165,099	$1,859	$111,218
Basic:	'	'	'
Continuing operations	$2.98	$1.72	$2.40
Discontinued operations	$0.07	($1.68)	($0.18)
Basic earnings per common share	$3.05	$0.04	$2.22
Diluted:	'	'	'
Continuing operations	$2.87	$1.65	$2.30
Discontinued operations	$0.07	($1.62)	($0.18)
Diluted earnings per common share	$2.94	$0.03	$2.12
Weighted average number of common shares outstanding:	'	'	'
Basic	54,126,545	51,509,366	50,198,954
Diluted	56,247,173	53,714,375	52,474,238

Consolidated_Statements_Of_Ope1

Consolidated Statements Of Operations Consolidated Statements of Operations (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Statements of Operations [Abstract]	'	'	'
Discontinued Operation, Tax Effect of Discontinued Operation	$2,284	($47,741)	($4,165)

Consolidated_Statement_Of_Comp

Consolidated Statement Of Comprehensive Earnings (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]	'	'	'
Net earnings (loss)	$165,718	($11,295)	$108,363
Reclassification adjustment, net of tax	-875	-1,789	-549
Change in unrealized (loss) gain on investments, net of tax	-6,934	1,217	-114
Other comprehensive earnings (loss)	-7,809	-572	-663
Comprehensive earnings (loss)	157,909	-11,867	107,700
Comprehensive earnings (loss) attributable to the noncontrolling interest	619	-13,154	-2,855
Comprehensive earnings attributable to Centene Corporation	$157,290	$1,287	$110,555

Consolidated_Statement_Of_Stoc

Consolidated Statement Of Stockholders' Equity (USD $)	Total	Centene Stockholders' Equity - Common Stock [Member]	Centene Stockholders' Equity - Additional Paid-In Capital [Member]	Centene Stockholders' Equity - Accumulated Other Comprehensive Income [Member]	Centene Stockholders' Equity - Retained Earnings [Member]	Centene Stockholders' Equity - Treasury Stock [Member]	Non Controlling Interest [Member]
In Thousands, except Share data, unless otherwise specified
Balance at Dec. 31, 2010	$797,055	$52	$384,206	$6,424	$453,743	($50,486)	$3,116
Balance (in shares) at Dec. 31, 2010	'	52,172,037	'	'	'	2,555,213	'
Net Income (Loss) Attributable to Parent	111,218	'	'	'	'	'	'
Comprehensive Earnings:	'	'	'	'	'	'	'
Net earnings (loss)	108,363	'	'	'	111,218	'	-2,855
Change in unrealized investment gain, net of tax	-663	'	'	-663	'	'	'
Comprehensive earnings (loss)	107,700	'	'	'	'	'	'
Common stock issued for employee benefit plans	15,437	2	15,435	'	'	'	'
Common stock issued for employee benefit plans (in shares)	'	1,414,689	'	'	'	'	'
Exercise of stock warrants	1,172	'	'	'	'	1,172	'
Exercise of stock warrants shares	'	'	'	'	'	-50,000	'
Common stock repurchases	-7,809	'	'	'	'	-7,809	'
Common stock repurchases (in shares)	'	'	'	'	'	216,895	'
Stock compensation expense	18,171	'	18,171	'	'	'	'
Excess tax benefit from stock compensation	4,169	'	4,169	'	'	'	'
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	813	'	'	'	'	'	813
Deconsolidation of Noncontrolling interest	-289	'	'	'	'	'	-289
Balance at Dec. 31, 2011	936,419	54	421,981	5,761	564,961	-57,123	785
Balance (in shares) at Dec. 31, 2011	'	53,586,726	'	'	'	2,722,108	'
Net Income (Loss) Attributable to Parent	1,859	'	'	'	'	'	'
Comprehensive Earnings:	'	'	'	'	'	'	'
Net earnings (loss)	-11,295	'	'	'	1,859	'	-13,154
Change in unrealized investment gain, net of tax	-572	'	'	-572	'	'	'
Comprehensive earnings (loss)	-11,867	'	'	'	'	'	'
Common stock issued for employee benefit plans	16,726	1	16,725	'	'	'	'
Common stock issued for employee benefit plans (in shares)	'	1,752,434	'	'	'	'	'
Common stock repurchases	-12,741	'	'	'	'	-12,741	'
Common stock repurchases (in shares)	287,804	'	'	'	'	287,804	'
Stock compensation expense	25,332	'	25,332	'	'	'	'
Excess tax benefit from stock compensation	10,999	'	10,999	'	'	'	'
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	1,092	'	'	'	'	'	1,092
Redemption / purchase of noncontrolling interest	-12,193	'	-24,181	'	'	'	11,988
Balance at Dec. 31, 2012	953,767	55	450,856	5,189	566,820	-69,864	711
Balance (in shares) at Dec. 31, 2012	52,329,248	55,339,160	'	'	'	3,009,912	'
Net Income (Loss) Attributable to Parent	165,099	'	'	'	165,099	'	'
Comprehensive Earnings:	'	'	'	'	'	'	'
Net earnings (loss)	165,718	'	'	'	'	'	619
Change in unrealized investment gain, net of tax	-7,809	'	'	-7,809	'	'	'
Comprehensive earnings (loss)	157,909	'	'	'	'	'	'
Equity issued in connection with acquisition	75,407	2	75,405	'	'	'	'
Stock Issued During Period, Shares, Acquisitions	'	1,716,690	'	'	'	'	'
Stock Issued During Period, Value, New Issues	15,225	0	15,225	'	'	'	'
Stock Issued During Period, Shares, New Issues	342,640	342,640	'	'	'	'	'
Common stock issued for employee benefit plans	9,798	2	9,796	'	'	'	'
Common stock issued for employee benefit plans (in shares)	'	1,274,725	'	'	'	'	'
Common stock repurchases	-19,779	'	'	'	'	-19,779	'
Common stock repurchases (in shares)	344,064	'	'	'	'	344,064	'
Stock compensation expense	36,656	'	36,656	'	'	'	'
Excess tax benefit from stock compensation	6,388	'	6,388	'	'	'	'
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	8,068	'	'	'	'	'	8,068
Balance at Dec. 31, 2013	$1,243,439	$59	$594,326	($2,620)	$731,919	($89,643)	$9,398
Balance (in shares) at Dec. 31, 2013	55,319,239	58,673,215	'	'	'	3,353,976	'

Consolidated_Statements_Of_Sto

Consolidated Statements Of Stockholders' Equity (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Statement of Stockholders' Equity (Parenthetical) [Abstract]	'	'	'
Tax on unrealized investment gain	($4,438)	($296)	($334)

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:	'	'	'
Net earnings (loss)	$165,718	($11,295)	$108,363
Adjustments to reconcile net earnings (loss) to net cash provided by operating activities	'	'	'
Depreciation and amortization	67,420	65,866	58,327
Stock compensation expense	36,656	25,332	18,171
Impairment loss	0	28,033	'
Gain on sale of investment in convertible note	0	-17,880	0
Debt extinguishment costs	0	0	8,488
Deferred income taxes	-2,293	-14,438	2,031
Changes in assets and liabilities	'	'	'
Premium and related receivables	-142,977	-116,558	-11,306
Other current assets	-79,588	-36,818	-11,812
Other assets	-736	2,825	-2
Medical claims liabilities	171,569	359,792	149,756
Unearned revenue	2,724	24,707	-109,082
Accounts payable and accrued expenses	151,712	-21,474	38,889
Other operating activities	12,321	-9,401	9,873
Net cash provided by operating activities	382,526	278,691	261,696
Cash flows from investing activities:	'	'	'
Capital expenditures	-67,835	-82,144	-73,708
Purchases of investments	-790,653	-695,687	-318,397
Sales and maturities of investments	579,161	589,921	267,404
Investments in acquisitions, net of cash acquired	-62,773	0	-4,375
Net cash used in investing activities	-342,100	-187,910	-129,076
Cash flows from financing activities:	'	'	'
Proceeds from exercise of stock options	8,983	15,912	15,815
Proceeds from borrowings	180,000	400,500	419,183
Proceeds from stock offering	15,225	0	0
Payment of long-term debt	-41,593	-218,234	-416,283
Excess tax benefits from stock compensation	6,380	10,996	4,435
Common stock repurchases	-19,779	-12,741	-7,809
Contribution from (to) noncontrolling interest	8,068	1,092	813
Purchase of noncontrolling interest	0	-14,429	0
Debt issue costs	-3,589	-3,623	-9,242
Net cash provided by financing activities	153,695	179,473	6,912
Net increase in cash and cash equivalents	194,121	270,254	139,532
Cash and cash equivalents, beginning of period	843,952	573,698	434,166
Cash and cash equivalents, end of period	1,038,073	843,952	573,698
Supplemental disclosures of cash flow information:	'	'	'
Interest paid	30,009	21,605	27,383
Income taxes paid	84,681	42,877	50,444
Equity issued in connection with acquisition	$75,425	$0	$0

Organization_And_Operations

Organization And Operations	12 Months Ended
	Dec. 31, 2013
Organization And Operations [Abstract]	'
Organization and Operations	'
	Organization and Operations
	Centene Corporation, or the Company, is a diversified, multi-line healthcare enterprise operating in two segments: Managed Care and Specialty Services. The Managed Care segment provides Medicaid and Medicaid-related health plan coverage to individuals through government subsidized programs, including Medicaid, the State Children's Health Insurance Program, or CHIP, Long Term Care (LTC), Foster Care, Medicare Special Needs Plans and the Supplemental Security Income Program, also known as the Aged, Blind or Disabled Program, or collectively ABD. The Specialty Services segment consists of our specialty companies offering auxiliary healthcare services and products to state programs, healthcare organizations, employer groups and other commercial organizations, as well as to our own subsidiaries. The health plan in Massachusetts, operated by our individual health insurance business, is included in the Specialty Services segment.

Summary_Of_Significant_Account

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of Centene Corporation and all majority owned subsidiaries and subsidiaries over which the Company exercises the power and control to direct activities significantly impacting financial performance. All material intercompany balances and transactions have been eliminated. The assets, liabilities and results of operations of Kentucky Spirit Health Plan are classified as discontinued operations for all periods presented.
	Certain amounts in the consolidated financial statements have been reclassified to conform to the 2013 presentation. These reclassifications have no effect on net earnings or stockholders' equity as previously reported.
	Use of Estimates
	The preparation of financial statements in conformity with generally accepted accounting principles in the United States, or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Future events and their effects cannot be predicted with certainty; accordingly, the accounting estimates require the exercise of judgment. The accounting estimates used in the preparation of the consolidated financial statements will change as new events occur, as more experience is acquired, as additional information is obtained and as the operating environment changes. The Company evaluates and updates its assumptions and estimates on an ongoing basis and may employ outside experts to assist in our evaluation, as considered necessary. Actual results could differ from those estimates.
	Cash and Cash Equivalents
	Investments with original maturities of three months or less are considered to be cash equivalents. Cash equivalents consist of money market funds and bank certificates of deposit and savings accounts.
	The Company maintains amounts on deposit with various financial institutions, which may exceed federally insured limits. However, management periodically evaluates the credit-worthiness of those institutions, and the Company has not experienced any losses on such deposits.
	Investments
	Short term investments include securities with maturities greater than three months to one year. Long term investments include securities with maturities greater than one year.
	Short term and long term investments are generally classified as available for sale and are carried at fair value. Certain equity investments are recorded using the cost or equity method. Unrealized gains and losses on investments available for sale are excluded from earnings and reported in accumulated other comprehensive income, a separate component of stockholders' equity, net of income tax effects. Premiums and discounts are amortized or accreted over the life of the related security using the effective interest method. The Company monitors the difference between the cost and fair value of investments. Investments that experience a decline in value that is judged to be other than temporary are written down to fair value and a realized loss is recorded in investment and other income. To calculate realized gains and losses on the sale of investments, the Company uses the specific amortized cost of each investment sold. Realized gains and losses are recorded in investment and other income.
	The Company uses the equity method to account for certain of its investment in entities that it does not control and for which it does not have the ability to exercise significant influence over operating and financial policies. These investments are recorded at the lower of their cost or fair value.
	Restricted Deposits
	Restricted deposits consist of investments required by various state statutes to be deposited or pledged to state agencies. These investments are classified as long term, regardless of the contractual maturity date, due to the nature of the states' requirements. The Company is required to annually adjust the amount of the deposit pledged to certain states.
	Fair Value Measurements
	In the normal course of business, the Company invests in various financial assets and incurs various financial liabilities. Fair values are disclosed for all financial instruments, whether or not such values are recognized in the Consolidated Balance Sheets. Management obtains quoted market prices and other observable inputs for these disclosures. The carrying amounts reported in the Consolidated Balance Sheets for cash and cash equivalents, premium and related receivables, unearned revenue, accounts payable and accrued expenses, and certain other current liabilities are carried at cost, which approximates fair value because of their short term nature.
	The following methods and assumptions were used to estimate the fair value of each financial instrument:
	•	Available for sale investments and restricted deposits: The carrying amount is stated at fair value, based on quoted market prices, where available. For securities not actively traded, fair values were estimated using values obtained from independent pricing services or quoted market prices of comparable instruments.
	•	Senior unsecured notes: Estimated based on third-party quoted market prices for the same or similar issues.
	•	Variable rate debt: The carrying amount of our floating rate debt approximates fair value since the interest rates adjust based on market rate adjustments.
	•	Interest rate swap: Estimated based on third-party market prices based on the forward 3-month LIBOR curve.
	Property, Software and Equipment
	Property, software and equipment are stated at cost less accumulated depreciation. Capitalized software includes certain costs incurred in the development of internal-use software, including external direct costs of materials and services and payroll costs of employees devoted to specific software development. Depreciation is calculated principally by the straight-line method over estimated useful lives. Leasehold improvements are depreciated using the straight-line method over the shorter of the expected useful life or the remaining term of the lease. Property, software and equipment are depreciated over the following periods:
	Fixed Asset		Depreciation Period
	Buildings and land improvements		5 - 40 years
	Computer hardware and software		2 - 7 years
	Furniture and equipment		3 - 10 years
	Leasehold improvements		1 - 20 years
	The carrying amounts of all long-lived assets are evaluated to determine if adjustment to the depreciation and amortization period or to the unamortized balance is warranted. Such evaluation is based principally on the expected utilization of the long-lived assets.
	The Company retains fully depreciated assets in property and accumulated depreciation accounts until it removes them from service. In the case of sale, retirement, or disposal, the asset cost and related accumulated depreciation balance is removed from the respective account, and the resulting net amount, less any proceeds, is included as a component of earnings from operations in the consolidated statements of operations.
	Goodwill and Intangible Assets
	Intangible assets represent assets acquired in purchase transactions and consist primarily of customer relationships, purchased contract rights, provider contracts, trade names and goodwill. Intangible assets are amortized using the straight-line method over the following periods:
	Intangible Asset		Amortization Period
	Purchased contract rights		5 - 15 years
	Provider contracts		4 - 15 years
	Customer relationships		5 - 15 years
	Trade names		7 - 20 years
	The Company tests for impairment of intangible assets as well as long-lived assets whenever events or changes in circumstances indicate that the carrying value of an asset or asset group (hereinafter referred to as “asset group”) may not be recoverable by comparing the sum of the estimated undiscounted future cash flows expected to result from use of the asset group and its eventual disposition to the carrying value. Such factors include, but are not limited to, significant changes in membership, state funding, state contracts and provider networks and contracts. If the sum of the estimated undiscounted future cash flows is less than the carrying value, an impairment determination is required. The amount of impairment is calculated by subtracting the fair value of the asset group from the carrying value of the asset group. An impairment charge, if any, is recognized within earnings from operations.
	The Company tests goodwill for impairment using a fair value approach. The Company is required to test for impairment at least annually, absent a triggering event including a significant decline in operating performance that would require an impairment assessment. Absent any impairment indicators, the Company performs its goodwill impairment testing during the fourth quarter of each year. The Company recognizes an impairment charge for any amount by which the carrying amount of goodwill exceeds its implied fair value.
	The Company first assesses qualitative factors to determine whether it is necessary to perform the two-step quantitative goodwill impairment test. The Company does not calculate the fair value of a reporting unit unless it determines, based on a qualitative assessment, that it is more likely than not that its fair value is less than its carrying amount.
	If the two-step quantitative test is deemed necessary, the Company uses discounted cash flows to establish the fair value as of the testing date. The discounted cash flow approach includes many assumptions related to future growth rates, discount factors, future tax rates, etc. Changes in economic and operating conditions impacting these assumptions could result in goodwill impairment in future periods. When available and as appropriate, the Company uses comparative market multiples to corroborate discounted cash flow results.
	Medical Claims Liability
	Medical claims liability includes claims reported but not yet paid, or inventory, estimates for claims incurred but not reported, or IBNR, and estimates for the costs necessary to process unpaid claims at the end of each period.  The Company estimates its medical claims liability using actuarial methods that are commonly used by health insurance actuaries and meet Actuarial Standards of Practice.  These actuarial methods consider factors such as historical data for payment patterns, cost trends, product mix, seasonality, utilization of healthcare services and other relevant factors.
	Actuarial Standards of Practice generally require that the medical claims liability estimates be adequate to cover obligations under moderately adverse conditions.  Moderately adverse conditions are situations in which the actual claims are expected to be higher than the otherwise estimated value of such claims at the time of estimate.  In many situations, the claims amounts ultimately settled will be different than the estimate that satisfies the Actuarial Standards of Practice. The Company includes in its IBNR an estimate for medical claims liability under moderately adverse conditions which represents the risk of adverse deviation of the estimates in its actuarial method of reserving.
	The Company uses its judgment to determine the assumptions to be used in the calculation of the required estimates. The assumptions it considers when estimating IBNR include, without limitation, claims receipt and payment experience (and variations in that experience), changes in membership, provider billing practices, healthcare service utilization trends, cost trends, product mix, seasonality, prior authorization of medical services, benefit changes, known outbreaks of disease or increased incidence of illness such as influenza, provider contract changes, changes to fee schedules, and the incidence of high dollar or catastrophic claims.
	The Company's development of the medical claims liability estimate is a continuous process which it monitors and refines on a monthly basis as additional claims receipts and payment information becomes available. As more complete claims information becomes available, the Company adjusts the amount of the estimates, and includes the changes in estimates in medical costs in the period in which the changes are identified. In every reporting period, the operating results include the effects of more completely developed medical claims liability estimates associated with previously reported periods. The Company consistently applies its reserving methodology from period to period. As additional information becomes known, it adjusts the actuarial model accordingly to establish medical claims liability estimates.
	The Company periodically reviews actual and anticipated experience compared to the assumptions used to establish medical costs. The Company establishes premium deficiency reserves if actual and anticipated experience indicates that existing policy liabilities together with the present value of future gross premiums will not be sufficient to cover the present value of future benefits, settlement and maintenance costs.
	Revenue Recognition
	The Company's health plans generate revenues primarily from premiums received from the states in which it operates health plans. The Company receives a fixed premium per member per month pursuant to its state contracts. The Company generally receives premium payments during the month it provides services and recognizes premium revenue during the period in which it is obligated to provide services to its members. In some instances, the Company's base premiums are subject to an adjustment, or risk score, based on the acuity of its membership. Generally, the risk score is determined by the State analyzing submissions of processed claims data to determine the acuity of the Company's membership relative to the entire state's Medicaid membership. Some states enact premium taxes, similar assessments and provider pass-through payments, collectively premium taxes, and these taxes are recorded as a separate component of both revenues and operating expenses. Some contracts allow for additional premiums related to certain supplemental services provided such as maternity deliveries.
	Revenues are recorded based on membership and eligibility data provided by the states, which is adjusted on a monthly basis by the states for retroactive additions or deletions to membership data. These eligibility adjustments are estimated monthly and subsequent adjustments are made in the period known. We continuously review and update those estimates as new information becomes available.  It is possible that new information could require us to make additional adjustments, which could be significant, to these estimates.
	The Company's specialty companies generate revenues under contracts with state programs, individuals, healthcare organizations and other commercial organizations, as well as from the Company's own subsidiaries. Revenues are recognized when the related services are provided or as ratably earned over the covered period of service.
	Premium and Related Receivables and Unearned Revenue
	Premium and service revenues collected in advance are recorded as unearned revenue. For performance-based contracts the Company does not recognize revenue subject to refund until data is sufficient to measure performance. Premiums and service revenues due to the Company are recorded as premium and related receivables and are recorded net of an allowance based on historical trends and management's judgment on the collectibility of these accounts. As the Company generally receives payments during the month in which services are provided, the allowance is typically not significant in comparison to total revenues and does not have a material impact on the presentation of the financial condition or results of operations. Activity in the allowance for uncollectible accounts for the years ended December 31, is summarized below:
		2013			2012			2011
	Allowances, beginning of year	781			639			17
	Amounts charged to expense	3,138			1,350			865
	Write-offs of uncollectible receivables	(2,801	)		(1,208	)		(243	)
	Allowances, end of year	1,118			781			639
	Significant Customers
	Centene receives the majority of its revenues under contracts or subcontracts with state Medicaid managed care programs. The current contracts expire on various dates between March 31, 2014 and October 31, 2018. States whose aggregate annual contract value exceeded 10% of annual revenues and the respective percentage of the Company's total revenues for the years ended December 31, are as follows:
	2013			2012			2011
	Texas	37%		Texas	40%		Georgia	15%
						Ohio	12%
						Texas	21%
Reinsurance
Centene's subsidiaries report reinsurance premiums as medical costs, while related reinsurance recoveries are reported as deductions from medical costs. The Company limits its risk of certain catastrophic losses by maintaining high deductible reinsurance coverage.
Other Income (Expense)
Other income (expense) consists principally of investment income, interest expense and equity method earnings from investments. Investment income is derived from the Company's cash, cash equivalents, restricted deposits and investments. Interest expense relates to borrowings under the senior notes, interest rate swap, credit facilities, interest on capital leases and credit facility fees.
Income Taxes
Deferred tax assets and liabilities are recorded for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax law or tax rates is recognized in income in the period that includes the enactment date.
Valuation allowances are provided when it is considered more likely than not that deferred tax assets will not be realized. In determining if a deductible temporary difference or net operating loss can be realized, the Company considers future reversals of existing taxable temporary differences, future taxable income, taxable income in prior carryback periods and tax planning strategies.
Contingencies
The Company accrues for loss contingencies associated with outstanding litigation, claims and assessments for which it has determined it is probable that a loss contingency exists and the amount of loss can be reasonably estimated. The Company expenses professional fees associated with litigation claims and assessments as incurred.
Stock Based Compensation
The fair value of the Company's employee share options and similar instruments are estimated using the Black-Scholes option-pricing model. That cost is recognized over the period during which an employee is required to provide service in exchange for the award. Excess tax benefits related to stock compensation are presented as a cash inflow from financing activities.
Recent Accounting Pronouncements
In 2011, the Financial Accounting Standards Board issued accounting guidance for the health insurance industry's annual fees mandated by the Patient Protection and Affordable Care Act. The fees will be imposed beginning in 2014 based on the Company's share of the industry's net premiums written during the preceding calendar year. In addition, these fees will not be tax deductible. Under the guidance, the liability for the fee will be estimated and recorded in full each year beginning in 2014 when health insurance is first provided. A corresponding deferred cost will be recorded and amortized to operating expense over the calendar year.

Noncontolling_Interest_and_Acq

Noncontolling Interest and Acquisitions	12 Months Ended
	Dec. 31, 2013
Noncontrolling Interest and Acquisitions Disclosure [Abstract]	'
Noncontrolling Interest and Acquisitions	'
	Noncontrolling Interest and Acquisition
	Noncontrolling Interest
	The Company has consolidated subsidiaries where it maintains less than 100% ownership.  The Company’s ownership interest for each subsidiary as of December 31, are as follows:
			2013		2012			2011
	Casenet		100	%	100	%		81	%
	Centurion		51	%	51	%		51	%
	Louisiana Healthcare Connections		100	%	100	%		51	%
	Home State Health Plan		95	%	95	%		—	%
	Casenet. During 2011, the Company increased its ownership interest in Casenet to 81% and in December 2012, acquired the remaining ownership interest for $4,429. The excess purchase price over the noncontrolling interest was recorded to additional paid in capital, net of the related deferred tax asset. Casenet is recorded in the Specialty Services segment.
	Centurion. During 2011, the Company began operations as a 51% joint venture partner with MHM Services Inc. as Centurion. In July 2013, Centurion began operating under a new contract with the Department of Corrections in Massachusetts to provide comprehensive healthcare services to individuals incarcerated in Massachusetts state correctional facilities and in September 2013, began operating under a new contract to provide comprehensive healthcare services to individuals incarcerated in Tennessee state correctional facilities. Centurion is recorded in the Specialty Services segment.
	Home State Health Plan. In July 2012, the Company began operations as a 95% joint venture partner, operating under a new contract with the Office of Administration for Missouri to serve Medicaid beneficiaries in the Eastern, Central, and Western Managed Care Regions of the state.
	Louisiana Healthcare Connections. In February 2012, the Company began operations under a new contract in Louisiana through a joint venture subsidiary, Louisiana Healthcare Connections. The Company initially owned a 51% interest in the subsidiary and in October 2012, acquired the remaining noncontrolling interest for $10,000. The purchase price in excess of the noncontrolling interest was recorded to additional paid in capital. The operating results of Louisiana are included in the Company's Managed Care segment.
	Net income attributable to Centene Corporation and transfers from (to) noncontrolling interest entities are as follows:
		Year Ended December 31,
		2013			2012				2011
	Net earnings attributable to Centene Corporation	$	161,218		$	88,533			$	120,518
	Transfers from (to) the noncontrolling interest:
	Decrease in equity for purchase of, distribution to and redemption of noncontrolling interest	—			(12,193		)		(289		)
	Increase in equity for distributions from and consolidation of noncontrolling interest	8,068			1,092				813
	Net transfers from (to) noncontrolling interest	8,068			(11,101		)		524
	Changes from net earnings attributable to Centene Corporation and net transfers from (to) the noncontrolling interest	$	169,286		$	77,432			$	121,042
	Acquisition
	AcariaHealth. In April 2013, the Company acquired 100% of AcariaHealth, a specialty pharmacy company, for $142,495 in total consideration. The transaction consideration was financed through a combination of $75,425 of Centene common stock and $67,070 of cash on hand. The Company also sold 342,640 shares of common stock for $15,225 related to funding the escrow account for the acquisition. The Company's allocation of fair value resulted in goodwill of $92,144 and other identifiable intangible assets of $35,000. The goodwill is not deductible for income tax purposes. The acquisition is recorded in the Specialty Services segment.
	Pro forma disclosures related to the acquisitions have been excluded as immaterial.

Discontinued_Operations_Notes

Discontinued Operations (Notes)	12 Months Ended
	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	'
	4. Discontinued Operations: Kentucky Spirit Health Plan
	In October 2012, the Company notified the Kentucky Cabinet for Health and Family Services (Cabinet) that it was exercising a contractual right that it believes allows the Company to terminate its Medicaid managed care contract with the Commonwealth of Kentucky (Commonwealth) effective July 5, 2013.  As of July 6, 2013, our subsidiary, Kentucky Spirit Health Plan (KSHP), ceased serving Medicaid members in Kentucky. Accordingly, the results of operations of KSHP are presented as discontinued operations for all periods presented. The assets, liabilities and results of operations of KSHP are classified as discontinued operations for all periods presented beginning in 2011. KSHP was previously reported in the Managed Care segment.
	During the years ended December 31, 2013 and 2012, the Company incurred exit costs consisting primarily of lease termination fees and employee severance. The change in exit cost liability for KSHP is summarized as follows:
		Employee Benefits			Lease Termination			Total
	Balance, December 31, 2011	$	—		$	—		$	—
	Incurred	2,939			—			2,939
	Balance, December 31, 2012	2,939			—			2,939
	Incurred	434			735			1,169
	Paid	(2,837		)	—			(2,837		)
	Balance, December 31, 2013	$	536		$	735		$	1,271
	KSHP had remaining statutory capital of approximately $83,600 at December 31, 2013, which will be transferred to unregulated cash, subject to regulatory approval.
	Operating results for the discontinued operations are as follows:
		Year Ended December 31,
		2013			2012			2011
	Revenues	$	248,327		$	557,316		$	129,105
	Earnings (loss) before income taxes	$	6,165		$	(134,415	)	$	(13,465	)
	Net earnings (loss)	$	3,881		$	(86,674	)	$	(9,300	)
	Assets and liabilities of the discontinued operations are as follows:
		December 31, 2013			December 31, 2012
	Current assets	$	77,512		$	176,996
	Long term investments and restricted deposits	38,305			60,461
	Other assets	—			1,836
	Assets of discontinued operations	$	115,817		$	239,293
	Medical claims liability	$	27,637		$	111,141
	Accounts payable and accrued expenses	2,657			45,975
	Other liabilities	1,028			357
	Liabilities of discontinued operations	$	31,322		$	157,473

ShortTerm_And_LongTerm_Investm

Short-Term And Long-Term Investments And Restricted Deposits	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Short-Term And Long-Term Investments And Restricted Deposits	'
	Short term and Long term Investments and Restricted Deposits
	Short term and long term investments and restricted deposits by investment type consist of the following:
		December 31, 2013										December 31, 2012
		Amortized			Gross		Gross			Fair		Amortized			Gross		Gross			Fair
		Cost			Unrealized		Unrealized Losses			Value		Cost			Unrealized		Unrealized Losses			Value
					Gains										Gains
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	246,085		$	245	$	(7,494	)	$	238,836	$	110,941		$	581	$	(221	)	$	111,301
	Corporate securities	293,912			2,782		(608		)	296,086		290,691			4,615		(195		)	295,111
	Restricted certificates of deposit	5,891			—		—			5,891		5,890			—		—			5,890
	Restricted cash equivalents	26,642			—		—			26,642		14,455			—		—			14,455
	Municipal securities:
	General obligation	54,003			555		(136		)	54,422		85,440			1,157		(26		)	86,571
	Pre-refunded	10,835			82		—			10,917		5,337			85		—			5,422
	Revenue	68,801			545		(292		)	69,054		82,781			1,313		(30		)	84,064
	Variable rate demand notes	28,575			—		—			28,575		23,385			—		—			23,385
	Asset backed securities	138,803			579		(332		)	139,050		73,570			1,082		(15		)	74,637
	Mortgage backed securities	33,974			—		(83		)	33,891		—			—		—			—
	Cost and equity method investments	22,239			—		—			22,239		11,298			—		—			11,298
	Life insurance contracts	15,369			—		—			15,369		15,023			—		—			15,023
	Total	$	945,129		$	4,788	$	(8,945	)	$	940,972	$	718,811		$	8,833	$	(487	)	$	727,157
	The Company’s investments are classified as available-for-sale with the exception of life insurance contracts and certain cost and equity method investments.  The Company’s investment policies are designed to provide liquidity, preserve capital and maximize total return on invested assets with the focus on high credit quality securities.  The Company limits the size of investment in any single issuer other than U.S. treasury securities and obligations of U.S. government corporations and agencies.  The Company's mortgage backed securities are issued by the Federal National Mortgage Association and carry guarantees by the U.S. government. As of December 31, 2013, 52% of the Company’s investments in securities recorded at fair value that carry a rating by S&P or Moody’s were rated AAA/Aaa, 68% were rated AA-/Aa3 or higher, and 94% were rated A-/A3 or higher.  At December 31, 2013, the Company held certificates of deposit, life insurance contracts and cost and equity method investments which did not carry a credit rating.
	The fair value of available-for-sale investments with gross unrealized losses by investment type and length of time that individual securities have been in a continuous unrealized loss position were as follows:
		December 31, 2013										December 31, 2012
		Less Than 12 Months					12 Months or More					Less Than 12 Months					12 Months or More
		Unrealized Losses			Fair		Unrealized Losses			Fair		Unrealized Losses			Fair		Unrealized Losses			Fair
					Value					Value					Value					Value
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	(6,188	)	$	172,365	$	(1,307	)	$	26,454	$	(219	)	$	56,033	$	(2	)	$	201
	Corporate securities	(400		)	52,725		(207		)	5,020		(195		)	44,208		—			—
	Municipal securities:
	General obligation	(72		)	3,480		(63		)	2,426		(26		)	7,930		—			—
	Revenue	(292		)	27,789		—			—		(30		)	3,090		—			—
	Asset backed securities	(333		)	37,689		—			—		(15		)	8,192		—			—
	Mortgage backed securities	(83		)	33,891		—			—		—			—		—			—
	Total	$	(7,368	)	$	327,939	$	(1,577	)	$	33,900	$	(485	)	$	119,453	$	(2	)	$	201
	As of December 31, 2013, the gross unrealized losses were generated from 83 positions out of a total of 343 positions.  The decline in fair value of fixed income securities is a result of movement in interest rates subsequent to the purchase of the security.
	For each security in an unrealized loss position, the Company assesses whether it intends to sell the security or if it is more likely than not the Company will be required to sell the security before recovery of the amortized cost basis for reasons such as liquidity, contractual or regulatory purposes.  If the security meets this criterion, the decline in fair value is other-than-temporary and is recorded in earnings.  The Company does not intend to sell these securities prior to maturity and it is not likely that the Company will be required to sell these securities prior to maturity; therefore, there is no indication of other than temporary impairment for these securities.
	The contractual maturities of short term and long term investments and restricted deposits are as follows:
		December 31, 2013										December 31, 2012
		Investments					Restricted Deposits					Investments					Restricted Deposits
		Amortized			Fair		Amortized			Fair		Amortized			Fair		Amortized			Fair
		Cost			Value		Cost			Value		Cost			Value		Cost			Value
	One year or less	$	101,537		$	102,126	$	40,633		$	40,637	$	136,997		$	138,101	$	33,897		$	33,928
	One year through five years	609,755			610,589		6,301			6,309		429,053			435,728		358			358
	Five years through ten years	157,003			151,221		—			—		93,907			93,778		—			—
	Greater than ten years	29,900			30,090		—			—		24,599			25,264		—			—
	Total	$	898,195		$	894,026	$	46,934		$	46,946	$	684,556		$	692,871	$	34,255		$	34,286
	Actual maturities may differ from contractual maturities due to call or prepayment options.  Asset backed and mortgage backed securities are included in the one year through five years category, while cost and equity method investments and life insurance contracts are included in the five years through ten years category.  The Company has an option to redeem at amortized cost substantially all of the securities included in the greater than ten years category listed above.
	The Company continuously monitors investments for other-than-temporary impairment.  Certain investments have experienced a decline in fair value due to changes in credit quality, market interest rates and/or general economic conditions.  The Company recognizes an impairment loss for cost and equity method investments when evidence demonstrates that it is other-than-temporarily impaired.  Evidence of a loss in value that is other than temporary may include the absence of an ability to recover the carrying amount of the investment or the inability of the investee to sustain a level of earnings that would justify the carrying amount of the investment.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	Assets and liabilities recorded at fair value in the consolidated balance sheets are categorized based upon the extent to which the fair value estimates are based upon observable or unobservable inputs.  Level inputs are as follows:
	Level Input:		Input Definition:
	Level I		Inputs are unadjusted, quoted prices for identical assets or liabilities in active markets at the measurement date.
	Level II		Inputs other than quoted prices included in Level I that are observable for the asset or liability through corroboration with market data at the measurement date.
	Level III		Unobservable inputs that reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date.
	The following table summarizes fair value measurements by level at December 31, 2013, for assets and liabilities measured at fair value on a recurring basis:
		Level I		Level II		Level III		Total
	Assets
	Cash and cash equivalents	$	974,304	$	—	$	—	$	974,304
	Investments available for sale:
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	212,185	$	12,238	$	—	$	224,423
	Corporate securities	—		296,086		—		296,086
	Municipal securities:
	General obligation	—		54,422		—		54,422
	Pre-refunded	—		10,917		—		10,917
	Revenue	—		69,054		—		69,054
	Variable rate demand notes	—		28,575		—		28,575
	Asset backed securities	—		139,050		—		139,050
	Mortgage backed securities	$	—	$	33,891	$	—	$	33,891
	Total investments	$	212,185	$	644,233	$	—	$	856,418
	Restricted deposits available for sale:
	Cash and cash equivalents	$	26,642	$	—	$	—	$	26,642
	Certificates of deposit	5,891		—		—		5,891
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	14,413		—		—		14,413
	Total restricted deposits	$	46,946	$	—	$	—	$	46,946
	Other long term assets:
	Interest rate swap contract	$	—	$	9,576	$	—	$	9,576
	Total assets at fair value	$	1,233,435	$	653,809	$	—	$	1,887,244
	The following table summarizes fair value measurements by level at December 31, 2012, for assets and liabilities measured at fair value on a recurring basis:
		Level I		Level II		Level III		Total
	Assets
	Cash and cash equivalents	$	745,933	$	—	$	—	$	745,933
	Investments available for sale:
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	57,114	$	40,246	$	—	$	97,360
	Corporate securities	—		295,111		—		295,111
	Municipal securities:
	General obligation	—		86,571		—		86,571
	Pre-refunded	—		5,422		—		5,422
	Revenue	—		84,064		—		84,064
	Variable rate demand notes	—		23,385		—		23,385
	Asset backed securities	—		74,637		—		74,637
	Mortgage backed securities	—		—		—		—
	Total investments	$	57,114	$	609,436	$	—	$	666,550
	Restricted deposits available for sale:
	Cash and cash equivalents	$	14,455	$	—	$	—	$	14,455
	Certificates of deposit	5,890		—		—		5,890
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	13,941		—		—		13,941
	Total restricted deposits	$	34,286	$	—	$	—	$	34,286
	Other long term assets:
	Interest rate swap contract	$	—	$	16,304	$	—	$	16,304
	Total assets at fair value	$	837,333	$	625,740	$	—	$	1,463,073
	The Company periodically transfers U.S. Treasury securities and obligations of U.S. government corporations and agencies between Level I and Level II fair value measurements dependent upon the level of trading activity for the specific securities at the measurement date.  The Company’s policy regarding the timing of transfers between Level I and Level II is to measure and record the transfers at the end of the reporting period.  At December 31, 2013, there were $1,143 of transfers from Level I to Level II and $26,301 of transfers from Level II to Level I.  The Company utilizes matrix pricing services to estimate fair value for securities which are not actively traded on the measurement date.  The Company designates these securities as Level II fair value measurements.  The aggregate carrying amount of the Company’s life insurance contracts and other non-majority owned investments, which approximates fair value, was $37,608 and $26,321 as of December 31, 2013 and December 31, 2012, respectively.

Notes_Receivable

Notes Receivable	12 Months Ended
	Dec. 31, 2013
Notes Receivable [Abstract]	'
Note Receivable	'
	Notes Receivable
	Between July 2008 and October 2011, the Company made an investment of $30,000 in secured notes receivable to a third party as part of an investment in certain Medicaid and Medicare related businesses. The notes included a feature to convert the note balance into an equity ownership in the underlying businesses.
	In September 2012, the Company executed an agreement with the borrower whereby the borrower agreed to pay the Company total consideration of $50,000 for retirement of the outstanding notes and equity ownership conversion feature. Under the terms of the agreement, the borrower paid the Company $30,000 in December 2012, and agreed to pay the Company $10,000 by September 30, 2013 and $10,000 by September 30, 2014. All outstanding balances are secured by liens on certain underlying businesses as well as guaranteed personally by the principal owner of the businesses. The $10,000 notes to be paid on or before September 30, 2013 and September 30, 2014 are non-interest bearing and, as a result, total consideration was discounted by $2,120 to reflect imputation of interest. As a result, during the third quarter of 2012, the Company recorded a pre-tax gain of $17,880 in other income representing the fair value of the total consideration in excess of the carrying value of the loans on the Company's balance sheet. As of December 31, 2013, the Company has a remaining receivable of $9,483 associated with this transaction.

Property_Software_And_Equipmen

Property, Software And Equipment	12 Months Ended
	Dec. 31, 2013
Property, Software and Equipment [Abstract]	'
Property, Software and Equipment	'
	Property, Software and Equipment
	Property, software and equipment consist of the following as of December 31:
		2013			2012
	Computer software	$	184,983		$	164,755
	Building	206,058			193,186
	Land	69,705			70,276
	Computer hardware	69,087			57,389
	Furniture and office equipment	53,180			43,136
	Leasehold improvements	56,816			49,808
		639,829			578,550
	Less accumulated depreciation	(244,422		)	(202,657		)
	Property, software and equipment, net	$	395,407		$	375,893
	As of December 31, 2013 and 2012, the Company had assets acquired under capital leases included above of $5,815 and $6,133, net of accumulated amortization of $1,782 and $1,595, respectively. Amortization on assets under capital leases charged to expense is included in depreciation expense. Depreciation expense for the years ended December 31, 2013, 2012 and 2011 was $52,234, $48,942 and $42,098, respectively.

Goodwill_And_Intangible_Assets

Goodwill And Intangible Assets	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets [Abstract]	'
Goodwill and Intangible Assets Disclosure	'
	Goodwill and Intangible Assets
	During the second quarter of 2012, the Company's subsidiary, Celtic Insurance Company, experienced a high level of medical costs for individual health policies, especially for recently issued policies related to members converted from another insurer during the first quarter of 2012. Additionally, in June 2012, the U.S. Supreme Court upheld the constitutionality of the Patient Protection and Affordable Care Act which limits the profitability of the individual health insurance business because of minimum medical loss ratios, guaranteed issue policies, and increased competition in the exchange market. As a result of these factors, the Company conducted an impairment analysis of the identifiable intangible assets and goodwill of the Celtic reporting unit. The impairment analysis resulted in goodwill and intangible asset impairments of $28,033, recorded as an impairment loss in the consolidated statement of operations. The impaired identifiable intangible assets of $2,340 and goodwill of $25,693 were reported under the Specialty Services segment; $26,589 of the impairment loss is not deductible for income tax purposes.
	The following table summarizes the changes in goodwill by operating segment:
		Managed Care			Specialty Services			Total
	Balance as of December 31, 2011	$	151,402		$	130,579		$	281,981
	Impairment	—			(25,693		)	(25,693		)
	Balance as of December 31, 2012	151,402			104,886			256,288
	Acquisition	—			92,144			92,144
	Balance as of December 31, 2013	$	151,402		$	197,030		$	348,432
	Goodwill acquisitions and other adjustments were related to the acquisitions and finalization of fair value allocations discussed in Note 3, Noncontrolling Interest and Acquisitions.
	Intangible assets at December 31, consist of the following:
								Weighted Average Life in Years
		2013			2012			2013		2012
	Purchased contract rights	$	21,988		$	21,988		7.5		7.5
	Provider contracts	35,537			2,737			13.2		9.8
	Customer relationships	13,396			13,396			8		8
	Trade names	8,695			6,495			18.9		16.3
	Intangible assets	79,616			44,616			11.1		9.1
	Less accumulated amortization:
	Purchased contract rights	(13,459		)	(11,010		)
	Provider contracts	(3,767		)	(1,241		)
	Customer relationships	(11,425		)	(10,214		)
	Trade names	(2,185		)	(1,883		)
	Total accumulated amortization	(30,836		)	(24,348		)
	Intangible assets, net	$	48,780		$	20,268
	Amortization expense was $6,489, $4,822 and $5,561 for the years ended December 31, 2013, 2012 and 2011 respectively. Estimated total amortization expense related to intangible assets for each of the five succeeding fiscal years is as follows:
	Year		Expense
	2014		$	6,800
	2015		5,900
	2016		5,900
	2017		4,400
	2018		2,600

Medical_Claims_Liability

Medical Claims Liability	12 Months Ended
	Dec. 31, 2013
Medical Claims Liability [Abstract]	'
Medical Claims Liability	'
	Medical Claims Liability
	The change in medical claims liability is summarized as follows:
		Year Ended December 31,
		2013			2012			2011
	Balance, January 1,	$	815,161		$	518,840		$	456,765
	Incurred related to:
	Current year	9,072,867			6,836,177			4,256,645
	Prior years	(78,226		)	(55,096		)	(65,377		)
	Total incurred	8,994,641			6,781,081			4,191,268
	Paid related to:
	Current year	7,975,367			6,024,720			3,744,475
	Prior years	722,726			460,040			384,718
	Total paid	8,698,093			6,484,760			4,129,193
	Balance, December 31,	$	1,111,709		$	815,161		$	518,840
	Changes in estimates of incurred claims for prior years are primarily attributable to reserving under moderately adverse conditions. In addition, claims processing initiatives yielded increased claim payment recoveries and coordination of benefits related to prior year dates of service. Changes in medical utilization and cost trends and the effect of medical management initiatives may also contribute to changes in medical claim liability estimates.  While the Company has evidence that medical management initiatives are effective on a case by case basis, medical management initiatives primarily focus on events and behaviors prior to the incurrence of the medical event and generation of a claim. Accordingly, any change in behavior, leveling of care, or coordination of treatment occurs prior to claim generation and as a result, the costs prior to the medical management initiative are not known by the Company. Additionally, certain medical management initiatives are focused on member and provider education with the intent of influencing behavior to appropriately align the medical services provided with the member's acuity. In these cases, determining whether the medical management initiative changed the behavior cannot be determined. Because of the complexity of its business, the number of states in which it operates, and the volume of claims that it processes, the Company is unable to practically quantify the impact of these initiatives on its changes in estimates of IBNR.
	The Company had reinsurance recoverables related to medical claims liability of $10,427 and $9,094 at December 31, 2013 and 2012, respectively, included in premium and related receivables.
	The Company periodically reviews actual and anticipated experience compared to the assumptions used to establish medical costs. The Company establishes premium deficiency reserves if actual and anticipated experience indicates that existing policy liabilities together with the present value of future gross premiums will not be sufficient to cover the present value of future benefits, settlement and maintenance costs.

Debt

Debt	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Debt	'
	Debt
	Debt consists of the following:
		December 31, 2013			December 31, 2012
	Senior notes, at par	$	425,000		$	425,000
	Unamortized premium on senior notes	6,052			7,823
	Interest rate swap fair value	9,576			16,304
	Senior notes	440,628			449,127
	Revolving credit agreement	150,000			—
	Mortgage notes payable	72,785			84,081
	Capital leases and other	5,349			5,646
	Total debt	668,762			538,854
	Less current portion	(3,065		)	(3,373		)
	Long term debt	$	665,697		$	535,481
	Senior Notes
	In May 2011, the Company issued $250,000 non-callable 5.75% Senior Notes due June 1, 2017 (the $250,000 Notes) at a discount to yield 6%. In connection with the May 2011 issuance, the Company entered into an interest rate swap for a notional amount of $250,000. Gains and losses due to changes in the fair value of the interest rate swap completely offset changes in the fair value of the hedged portion of the underlying debt and are recorded as an adjustment to the $250,000 Notes. At December 31, 2013, the fair value of the interest rate swap increased the fair value of the notes by $9,576 and the variable interest rate of the swap was 3.74%.
	In November 2012, the Company issued an additional $175,000 non-callable 5.75% Senior Notes due June 1, 2017 ($175,000 Add-on Notes) at a premium to yield 4.29%. The indenture governing the $250,000 Notes and the $175,000 Add-on Notes contains non-financial and financial covenants, including requirements of a minimum fixed charge coverage ratio. Interest is paid semi-annually in June and December. At December 31, 2013, the total net unamortized debt premium on the $250,000 Notes and $175,000 Add-on Notes was $6,052.
	Revolving Credit Agreement
	In May 2013, the Company entered into a new unsecured $500,000 revolving credit facility and terminated its previous $350,000 revolving credit facility. Borrowings under the agreement bear interest based upon LIBOR rates, the Federal Funds Rate or the Prime Rate. The agreement has a maturity date of June 1, 2018, provided it will mature 90 days prior to the maturity date of the Company's 5.75% Senior Notes due 2017 if such notes are not refinanced (or extended) or certain financial conditions are not met, including carrying $100,000 of unrestricted cash on deposit. As of December 31, 2013, the Company had $150,000 of borrowings outstanding under the agreement with a weighted average interest rate of 3.31%.
	The agreement contains non-financial and financial covenants, including requirements of minimum fixed charge coverage ratios, maximum debt-to-EBITDA ratios and minimum tangible net worth. The Company is required not to exceed a maximum debt-to-EBITDA ratio of 3.0 to 1.0. As of December 31, 2013, there were no limitations on the availability under the revolving credit agreement as a result of the debt-to-EBITDA ratio.
	Mortgage Notes Payable
	The Company has a non-recourse mortgage note of $72,785 at December 31, 2013 collateralized by its corporate headquarters building. The mortgage note is due January 1, 2021 and bears a 5.14% interest rate. The collateralized property had a net book value of $160,246 at December 31, 2013.
	The Company also had a mortgage note of $8,700 at December 31, 2012 collateralized by another building and parking garage. In June 2013, the Company repaid this mortgage note.
	Letters of Credit & Surety Bonds
	The Company had outstanding letters of credit of $28,757 as of December 31, 2013, which were not part of the revolving credit facility.  The letters of credit bore interest at 0.51% as of December 31, 2013. The Company had outstanding surety bonds of $102,568 as of December 31, 2013.
	Aggregate maturities for the Company's debt are as follows:
	2014		$	3,065
	2015		3,188
	2016		3,353
	2017		428,525
	2018		153,702
	Thereafter		61,301
	Total		$	653,134
	The fair value of outstanding debt was approximately $672,529 and $543,611 at December 31, 2013 and 2012, respectively.

Interest_Rate_Swap

Interest Rate Swap	12 Months Ended
	Dec. 31, 2013
Interest Rate Swap [Abstract]	'
Interest Rate Swap	'
	Interest Rate Swap
	In May 2011, the Company entered into $250,000 notional amount of interest rate swap agreements (Swap Agreements) that are scheduled to expire June 1, 2017. Under the Swap Agreements, the Company receives a fixed rate of 5.75% and pays a variable rate of the three month LIBOR plus 3.5% adjusted quarterly, which allows the Company to adjust $250,000 of its senior notes to a floating rate. The Company does not hold or issue any derivative instrument for trading or speculative purposes. At December 31, 2013, the variable rate was 3.74%.
	The Swap Agreements are formally designated and qualify as fair value hedges. The Swap Agreements are recorded at fair value in the Consolidated Balance Sheet in other assets or other liabilities. Gains and losses due to changes in fair value of the interest rate swaps completely offset changes in the fair value of the hedged portion of the underlying debt. Therefore, no gain or loss has been recognized due to hedge ineffectiveness. Offsetting changes in fair value of both the interest rate swaps and the hedged portion of the underlying debt both were recognized in interest expense in the Consolidated Statement of Operations.
	The fair value of the Swap Agreements as of December 31, 2013 was an asset of approximately $9,576, and is included in other long term assets in the Consolidated Balance Sheet. The fair value of the Swap Agreements excludes accrued interest and takes into consideration current interest rates and current likelihood of the swap counterparties' compliance with its contractual obligations.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2013
Stockholders' Equity Attributable to Parent [Abstract]	'
Stockholders' Equity	'
	Stockholders' Equity
	The Company has 10,000,000 authorized shares of preferred stock at $.001 par value. At December 31, 2013, there were no preferred shares outstanding.
	The Company's Board of Directors has authorized a stock repurchase program for up to 4,000,000 shares of the Company's common stock from time to time on the open market or through privately negotiated transactions. No duration has been placed on the repurchase program. The Company has 1,667,724 available shares remaining under the program for repurchases as of December 31, 2013. The Company reserves the right to discontinue the repurchase program at any time. During the year ended December 31, 2013, the Company did not repurchase any shares through this publicly announced program.
	As a component of the employee stock compensation plan, employees can use shares of stock which have vested to satisfy minimum statutory tax withholding obligations. As part of this plan, the Company repurchased 344,064 shares at an aggregate cost of $19,779 in 2013 and 287,804 shares at an aggregate cost of $12,741 in 2012. These shares are included in the Company's treasury stock.
	In April 2013, the Company completed the acquisition of AcariaHealth and as a result, issued 1,716,690 shares of Centene common stock to the selling stockholders. Additionally, the Company filed an equity shelf registration statement related to funding the escrow account for the acquisition and sold 342,640 shares of Centene common stock for $15,225.

Statutory_Capital_Requirements

Statutory Capital Requirements And Dividend Restrictions	12 Months Ended
	Dec. 31, 2013
Statutory Capital [Abstract]	'
Statutory Capital Requirements and Dividend Restriction	'
	Statutory Capital Requirements and Dividend Restrictions
	Various state laws require Centene's regulated subsidiaries to maintain minimum capital levels specified by each state and restrict the amount of dividends that may be paid without prior regulatory approval. At December 31, 2013 and 2012, Centene's subsidiaries, including Kentucky Spirit Health Plan, had aggregate statutory capital and surplus of $1,279,700 and $990,300, respectively, compared with the required minimum aggregate statutory capital and surplus of $686,400 and $617,000, respectively.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax [Abstract]	'
Income Taxes	'
	Income Taxes
	The consolidated income tax expense consists of the following for the years ended December 31:
		2013			2012			2011
	Current provision:
	Federal	$	120,858		$	47,528		$	63,388
	State and local	5,857			(4,368		)	5,157
	Total current provision	126,715			43,160			68,545
	Deferred provision	(19,635		)	4,252			2,142
	Total provision for income taxes	$	107,080		$	47,412		$	70,687
	The reconciliation of the tax provision at the U.S. Federal Statutory Rate to the provision for income taxes is as follows:
		2013			2012			2011
	Earnings from continuing operations, before income tax expense	$	268,917		$	122,791		$	188,350
	Less flow through noncontrolling interest	960			(2,539		)	(2,855		)
	Earnings from continuing operations, less noncontrolling interest, before income tax expense	267,957			125,330			191,205
	Tax provision at the U.S. federal statutory rate	93,785			43,866			66,922
	State income taxes, net of federal income tax benefit	2,871			(2,288		)	3,381
	Nondeductible goodwill impairment	—			8,487			—
	Nondeductible compensation	12,519			1,108			2,705
	Other, net	(2,095		)	(3,761		)	(2,321		)
	Income tax expense	$	107,080		$	47,412		$	70,687
	The tax effects of temporary differences which give rise to deferred tax assets and liabilities are presented below for the years ended December 31:
		2013			2012
	Deferred tax assets:
	Medical claims liability and other accruals	$	53,943		$	37,413
	State net operating loss carry forward	9,530			9,055
	Stock compensation	14,223			12,615
	Other	30,199			20,573
	Deferred tax assets	107,895			79,656
	Valuation allowance	(8,119		)	(8,180		)
	Net deferred tax assets	$	99,776		$	71,476
	Deferred tax liabilities:
	Intangible assets	$	18,278		$	12,441
	Prepaid assets	5,621			4,767
	Depreciation and amortization	30,411			31,741
	Other	1,615			5,624
	Deferred tax liabilities	$	55,925		$	54,573
	Net deferred tax assets	$	43,851		$	16,903
	The Company's deferred tax assets include federal and state net operating losses, or NOLs, of which $6,547 were acquired in business combinations. Accordingly, the total and annual deduction for those NOLs is limited by tax law. The Company's federal NOLs expire between the years 2020 and 2032 and the state NOLs expire between the years 2014 and 2034. Valuation allowances are recorded for those NOLs the Company believes are more likely than not to expire unused. During 2013 and 2012, the Company recorded valuation allowance additions in the tax provision of $1,301 and $2,093, respectively. In 2013 and 2012, the Company recorded valuation allowance reductions of $1,362 and $2,289, respectively.
	The Company maintains a reserve for uncertain tax positions that may be challenged by a tax authority. A roll-forward of the reserve is as follows:
		2013			2012
	Gross unrecognized tax benefits, beginning of period	$	7,870		$	13,552
	Gross increases:
	Current year tax positions	338			4,107
	Prior year tax positions	164			451
	Gross decreases:
	Prior year tax positions	—			(9,925		)
	Settlements	(4,390		)	(53		)
	Statute of limitation lapses	(708		)	(262		)
	Gross unrecognized tax benefits, end of period	$	3,274		$	7,870
	Included in the balance of unrecognized tax benefits at December 31, 2013 and 2012 were reserve balances of $3,274 and $4,095, respectively, that, if recognized, would decrease the effective tax rate on income from continuing operations. Also included in the December 31, 2012 reserve balance were liabilities of $3,775 that, if recognized, would have been recorded as an adjustment to deferred taxes.
	The Company recognizes interest accrued related to unrecognized tax benefits in the provision for income taxes. During the year ended December 31, 2013 and 2012, the Company recognized tax benefits generated from the net reduction in interest accrued of $310 and $170, respectively. Interest accrued, net of federal benefit, was $623, $933 and $1,157 as of December 31, 2013, 2012 and 2011, respectively. No penalties have been accrued.
	During 2013, the IRS concluded its examination of the Company's 2010 and 2011 federal tax returns. The Company files in numerous state jurisdictions with varying statutes of limitation. The unrecognized state tax benefits are related to returns open from 2009 to 2013.

Stock_Incentive_Plans

Stock Incentive Plans	12 Months Ended
	Dec. 31, 2013
Stock Incentive Plans [Abstract]	'
Stock Incentive Plans	'
	Stock Incentive Plans
	The Company's stock incentive plans allow for the granting of restricted stock or restricted stock unit awards and options to purchase common stock. Both incentive stock options and nonqualified stock options can be awarded under the plans. No option will be exercisable for longer than ten years after the date of grant. The plans have 1,414,240 shares available for future awards. Compensation expense for stock options and restricted stock unit awards is recognized on a straight-line basis over the vesting period, generally three to five years for stock options and 1 to 10 years for restricted stock or restricted stock unit awards. Certain restricted stock unit awards contain performance-based as well as service-based provisions. Certain awards provide for accelerated vesting if there is a change in control as defined in the plans. The total compensation cost that has been charged against income for the stock incentive plans was $36,153, $25,001 and $18,141 for the years ended December 31, 2013, 2012 and 2011, respectively. The total income tax benefit recognized in the income statement for stock-based compensation arrangements was $7,575, $8,952 and $5,804 for the years ended December 31, 2013, 2012 and 2011, respectively.
	Option activity for the year ended December 31, 2013 is summarized below:
		Shares			Weighted Average Exercise Price			Aggregate Intrinsic Value			Weighted Average Remaining Contractual Term
	Outstanding as of December 31, 2012	1,299,396			$	22.39
	Granted	10,000			44.58
	Exercised	(361,538	)		20.32
	Forfeited	(663	)		17.86
	Outstanding as of December 31, 2013	947,195			$	23.41		$	33,659		2.8
	Exercisable as of December 31, 2013	921,462			$	23.21		$	32,937		2.7
	The fair value of each option grant is estimated on the date of the grant using the Black-Scholes option-pricing model with the following weighted-average assumptions:
		Year Ended December 31,
		2013		2012 (1)		2011
	Expected life (in years)	5.1		—		5.2
	Risk-free interest rate	0.80%		—		0.90%
	Expected volatility	48.10%		—		49.90%
	Expected dividend yield	—		—		—
	(1) No options were awarded in the year ended December 31, 2012.
	For the years ended December 31, 2013, 2012 and 2011, the Company used a projected expected life for each award granted based on historical experience of employees' exercise behavior. The expected volatility is primarily based on historical volatility levels. The risk-free interest rates are based on the implied yield currently available on U.S. Treasury instruments with a remaining term equal to the expected life.
	Other information pertaining to option activity is as follows:
		Year Ended December 31,
		2013				2012 (1)			2011
	Weighted-average fair value of options granted	$	19.04			$	—		$	13.94
	Total intrinsic value of stock options exercised	$	12,845			$	24,120		$	11,744
	(1) No options were awarded in the year ended December 31, 2012.
	A summary of the Company's non-vested restricted stock and restricted stock unit shares as of December 31, 2013, and changes during the year ended December 31, 2013, is presented below:
		Shares			Weighted Average Grant Date Fair Value
	Non-vested balance as of December 31, 2012	2,058,908			$	37.25
	Granted	1,037,542			55.36
	Vested	(961,741	)		33.57
	Forfeited	(45,116	)		38.91
	Non-vested balance as of December 31, 2013	2,089,593			$	47.9
	The total fair value of restricted stock and restricted stock units vested during the years ended December 31, 2013, 2012 and 2011, was $49,032, $38,576 and $22,280, respectively.
	As of December 31, 2013, there was $87,901 of total unrecognized compensation cost related to non-vested share-based compensation arrangements granted under the plans; that cost is expected to be recognized over a weighted-average period of 1.7 years. The actual tax benefit realized for the tax deductions from disqualified dispositions of stock option exercises totaled $508, $1,078 and $955 for the years ended December 31, 2013, 2012 and 2011, respectively.
	The Company maintains an employee stock purchase plan and has issued 42,084 shares, 47,613 shares, and 34,966 shares in 2013, 2012 and 2011, respectively.

Retirement_Plan

Retirement Plan	12 Months Ended
	Dec. 31, 2013
Retirement Plan [Abstract]	'
Retirement Plan	'
	Retirement Plan
	Centene has a defined contribution plan which covers substantially all employees who are at least twenty-one years of age. Under the plan, eligible employees may contribute a percentage of their base salary, subject to certain limitations. Centene may elect to match a portion of the employee's contribution. Company expense related to matching contributions to the plan was $9,422, $6,771 and $5,119 during the years ended December 31, 2013, 2012 and 2011, respectively.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2013
Commitments [Abstract]	'
Commitments	'
	Commitments
	Centene and its subsidiaries lease office facilities and various equipment under non-cancelable operating leases which may contain escalation provisions. The rental expense related to these leases is recorded on a straight-line basis over the lease term, including rent holidays. Tenant improvement allowances are recorded as a liability and amortized against rent expense over the term of the lease. Rent expense was $30,562, $27,564 and $22,537 for the years ended December 31, 2013, 2012 and 2011, respectively. Annual non-cancelable minimum lease payments over the next five years and thereafter are as follows:
	2014	$	25,350
	2015	25,871
	2016	24,202
	2017	19,336
	2018	12,628
	Thereafter	18,800
		$	126,187

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2013
Contingencies [Abstract]	'
Contingencies	'
	Contingencies
	In October 2012, the Company notified the Kentucky Cabinet for Health and Family Services (Cabinet) that it was exercising a contractual right that it believes allows the Company to terminate its Medicaid managed care contract with the Commonwealth of Kentucky (Commonwealth) effective July 5, 2013.  The Company also filed a lawsuit in Franklin Circuit Court against the Commonwealth seeking a declaration of the Company's right to terminate the contract on July 5, 2013.  In April 2013, the Commonwealth answered that lawsuit and filed counterclaims against the Company seeking declaratory relief and damages.  In May 2013, the Franklin Circuit Court ruled that Kentucky Spirit does not have a contractual right to terminate the contract early.  Kentucky Spirit has appealed that ruling to the Kentucky Court of Appeals.
	The Company also filed a formal dispute with the Cabinet for damages incurred under the contract, which was later appealed to and denied by the Finance and Administration Cabinet.  In response, the Company filed a lawsuit in April 2013, in Franklin Circuit Court seeking damages against the Commonwealth for losses sustained due to the Commonwealth's alleged breaches. This lawsuit was subsequently consolidated with the original lawsuit for declaratory relief and continues to proceed.
	Kentucky Spirit's efforts to resolve issues with the Commonwealth were unsuccessful and on July 5, 2013, Kentucky Spirit proceeded with its previously announced exit.  The Commonwealth has alleged that Kentucky Spirit's exit constitutes a material breach of contract.  The Commonwealth seeks to recover substantial damages and to enforce its rights under Kentucky Spirit's $25,000 performance bond.  Any claim for damages by the Commonwealth may include the costs of transition and the additional costs to the Commonwealth to cover Kentucky Spirit's former members through July 5, 2014. Kentucky Spirit is pursuing its litigation claims for damages against the Commonwealth and will vigorously defend against any allegations that it has breached the contract.
	The resolution of the Kentucky litigation matters may result in a range of possible outcomes.  If the Company prevails on its claims, Kentucky Spirit would be entitled to damages under its lawsuit.  If the Commonwealth prevails, a liability to the Commonwealth could be recorded.  The Company is unable to estimate the ultimate outcome resulting from the Kentucky litigation.  As a result, the Company has not recorded any receivable or any liability for potential damages under the contract as of December 31, 2013.  While uncertain, the ultimate resolution of the pending litigation could have a material effect on the financial position, cash flow or results of operations of the Company in the period it is resolved or becomes known.
	Excluding the Kentucky matters discussed above, the Company is also routinely subjected to legal proceedings in the normal course of business.  While the ultimate resolution of such matters in the normal course of business is uncertain, the Company does not expect the results of any of these matters individually, or in the aggregate, to have a material effect on its financial position, results of operations or cash flows.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Earnings Per Share
	The following table sets forth the calculation of basic and diluted net earnings per common share for the years ended December 31:
		2013		2012			2011
	Earnings attributable to Centene Corporation:
	Earnings from continuing operations, net of tax	$	161,218	$	88,533		$	120,518
	Discontinued operations, net of tax	3,881		(86,674		)	(9,300		)
	Net earnings	$	165,099	$	1,859		$	111,218
	Shares used in computing per share amounts:
	Weighted average number of common shares outstanding	54,126,545		51,509,366			50,198,954
	Common stock equivalents (as determined by applying the treasury stock method)	2,120,628		2,205,009			2,275,284
	Weighted average number of common shares and potential dilutive common shares outstanding	56,247,173		53,714,375			52,474,238
	Net earnings per common share attributable to Centene Corporation:
	Basic:
	Continuing operations	$	2.98	$	1.72		$	2.4
	Discontinued operations	0.07		(1.68		)	(0.18		)
	Basic earnings per common share	$	3.05	$	0.04		$	2.22
	Diluted:
	Continuing operations	$	2.87	$	1.65		$	2.3
	Discontinued operations	0.07		(1.62		)	(0.18		)
	Diluted earnings per common share	$	2.94	$	0.03		$	2.12
	The calculation of diluted earnings per common share for 2013, 2012 and 2011 excludes the impact of 93,539 shares, 142,425 shares and 106,219 shares, respectively, related to anti-dilutive stock options, restricted stock and restricted stock units.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	Segment Information
	Centene operates in two segments: Managed Care and Specialty Services.  The Managed Care segment consists of Centene’s health plans including all of the functions needed to operate them.  The Specialty Services segment consists of Centene’s specialty companies offering auxiliary healthcare services and products. The health plan in Massachusetts, operated by our individual health insurance business, is included in the Specialty Services segment.
	Factors used in determining the reportable business segments include the nature of operating activities, existence of separate senior management teams, and the type of information presented to the Company's chief operating decision maker to evaluate all results of operations.
	In January 2013, the Company reclassified the health plan in Arizona, which is primarily a LTC operation, to the Managed Care segment. As a result, the financial results of the Arizona health plan have been reclassified from the Specialty Services segment to the Managed Care segment for all periods presented.
	Segment information as of and for the year ended December 31, 2013, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	9,740,720	$	785,320	$	—		$	10,526,040
	Premium and service revenues from internal customers	41,094		2,147,200		(2,188,294		)	—
	Total premium and service revenues	9,781,814		2,932,520		(2,188,294		)	10,526,040
	Earnings from operations	197,844		79,573		—			277,417
	Total assets	2,817,519		595,964		—			3,413,483
	Segment information as of and for the year ended December 31, 2012, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	7,124,720	$	556,911	$	—		$	7,681,631
	Premium and service revenues from internal customers	87,319		1,550,096		(1,637,415		)	—
	Total premium and service revenues	7,212,039		2,107,007		(1,637,415		)	7,681,631
	Earnings from operations	62,867		45,099		—			107,966
	Total assets	2,163,347		371,265		—			2,534,612
	Segment information as of and for the year ended December 31, 2011, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	4,571,430	$	480,472	$	—		$	5,051,902
	Premium and service revenues from internal customers	64,809		710,002		(774,811		)	—
	Total premium and service revenues	4,636,239		1,190,474		(774,811		)	5,051,902
	Earnings from operations	161,890		41,913		—			203,803
	Total assets	1,709,271		383,259		—			2,092,530

Quarterly_Selected_Financial_I

Quarterly Selected Financial Information	12 Months Ended
	Dec. 31, 2013
Quarterly Selected Financial Information [Abstract]	'
Quarterly Selected Financial Information	'
	Quarterly Selected Financial Information
	(In thousands, except share data and membership data)
	(Unaudited)
		For the Quarter Ended
		March 31,			June 30,			September 30,			December 31,
		2013			2013			2013			2013
	Total revenues	$	2,525,482		$	2,610,538		$	2,795,569		$	2,931,740
	Amounts attributable to Centene Corporation common shareholders:
	Earnings from continuing operations, net of income tax expense	$	22,639		$	40,289		$	50,325		$	47,965
	Discontinued operations, net of income tax expense (benefit)	363			(805		)	(952		)	5,275
	Net earnings	$	23,002		$	39,484		$	49,373		$	53,240
	Net earnings (loss) per common share attributable to Centene Corporation:
	Basic:
	Continuing operations	$	0.43		$	0.74		$	0.92		$	0.87
	Discontinued operations	0.01			(0.02		)	(0.02		)	0.1
	Basic earnings per common share	$	0.44		$	0.72		$	0.9		$	0.97
	Diluted:
	Continuing operations	$	0.41		$	0.71		$	0.88		$	0.84
	Discontinued operations	0.01			0.01			(0.01		)	0.09
	Diluted earnings per common share	$	0.42		$	0.72		$	0.87		$	0.93
	Health Benefits Ratio	90.2		%	88.4		%	87.8		%	88.1		%
	General & Administrative Expense Ratio	8.4		%	8.9		%	9.1		%	8.9		%
	Period end at-risk membership	2,553,400			2,563,400			2,612,500			2,723,200
		For the Quarter Ended
		March 31,			June 30,			September 30,			December 31,
		2012			2012			2012			2012
	Total revenues	$	1,562,809		$	1,967,362		$	2,308,075		$	2,272,050
	Amounts attributable to Centene Corporation common shareholders:
	Earnings (loss) from continuing operations, net of income tax expense (benefit)	$	27,072		$	(16,656	)	$	59,438		$	18,679
	Discontinued operations, net of income tax benefit	(3,094		)	(18,343		)	(55,619		)	(9,618		)
	Net earnings (loss)	$	23,978		$	(34,999	)	$	3,819		$	9,061
	Net earnings (loss) per common share attributable to Centene Corporation:
	Basic:
	Continuing operations	$	0.53		$	(0.32	)	$	1.15		$	0.36
	Discontinued operations	(0.06		)	(0.36		)	(1.08		)	(0.19		)
	Basic earnings per common share	$	0.47		$	(0.68	)	$	0.07		$	0.17
	Diluted:
	Continuing operations	$	0.51		$	(0.32	)	$	1.1		$	0.35
	Discontinued operations	(0.06		)	(0.36		)	(1.03		)	(0.18		)
	Diluted earnings per common share	$	0.45		$	(0.68	)	$	0.07		$	0.17
	Health Benefits Ratio	87.1		%	91.2		%	88.7		%	90.7		%
	General & Administrative Expense Ratio	10.4		%	8.5		%	8.4		%	8.4		%
	Period end at-risk membership	2,003,800			2,254,000			2,357,600			2,424,500

Condensed_Financial_Informatio

Condensed Financial Information Of Registrant	12 Months Ended
	Dec. 31, 2013
Condensed Financial Information of Registrant [Abstract]	'
Condensed Financial Information of Registrant	'
	Condensed Financial Information of Registrant
	Centene Corporation (Parent Company Only)
	Condensed Balance Sheets
	(In thousands, except share data)
		December 31,
		2013			2012
	ASSETS
	Current assets:
	Cash and cash equivalents	$	2,740		$	22,279
	Short term investments, at fair value (amortized cost $6,000 and $6,500, respectively)	6,000			6,500
	Other current assets	124,903			42,230
	Total current assets	133,643			71,009
	Long term investments, at fair value (amortized cost $8,070 and $1,356, respectively)	8,070			1,356
	Investment in subsidiaries	1,667,258			1,298,648
	Other long term assets	31,876			42,523
	Total assets	$	1,840,847		$	1,413,536
	LIABILITIES AND STOCKHOLDERS' EQUITY
	Current liabilities	$	4,460		$	4,333
	Long term debt	590,628			449,127
	Other long term liabilities	2,320			6,309
	Total liabilities	597,408			459,769
	Stockholders' equity:
	Common stock, $.001 par value; authorized 100,000,000 shares; 58,673,215 issued and 55,319,239 outstanding at December 31, 2013, and 55,339,160 issued and 52,329,248 outstanding at December 31, 2012	59			55
	Additional paid-in capital	594,326			450,856
	Accumulated other comprehensive income:
	Unrealized gain (loss) on investments, net of tax	(2,620		)	5,189
	Retained earnings	731,919			566,820
	Treasury stock, at cost (3,353,976 and 3,009,912 shares, respectively)	(89,643		)	(69,864		)
	Total Centene stockholders' equity	1,234,041			953,056
	Noncontrolling interest	9,398			711
	Total stockholders' equity	1,243,439			953,767
	Total liabilities and stockholders' equity	$	1,840,847		$	1,413,536
	See notes to condensed financial information of registrant.
	Centene Corporation (Parent Company Only)
	Condensed Statements of Operations
	(In thousands, except share data)
		Year Ended December 31,
		2013			2012			2011
	Expenses:
	General and administrative expenses	$	4,196		$	4,090		$	4,488
	Other income (expense):
	Investment and other income	983			19,921			(8,790		)
	Interest expense	(22,623		)	(15,757		)	(15,494		)
	Earnings (loss) before income taxes	(25,836		)	74			(28,772		)
	Income tax benefit	(15,191		)	(9,668		)	(12,825		)
	Net earnings (loss) before equity in subsidiaries	(10,645		)	9,742			(15,947		)
	Equity in earnings from subsidiaries	171,863			78,791			136,465
	Net earnings from continuing operations	$	161,218		$	88,533		$	120,518
	Net earnings per share from continuing operations:
	Basic earnings per common share	$	2.98		$	1.72		$	2.4
	Diluted earnings per common share	$	2.87		$	1.65		$	2.3
	Weighted average number of shares outstanding:
	Basic	54,126,545			51,509,366			50,198,954
	Diluted	56,247,173			53,714,375			52,474,238
	See notes to condensed financial information of registrant.
	Centene Corporation (Parent Company Only)
	Condensed Statements of Cash Flows
	(In thousands)
		Year Ended December 31,
		2013			2012			2011
	Cash flows from operating activities:
	Cash provided by operating activities	$	302,242		$	327,940		$	72,754
	Cash flows from investing activities:
Net dividends from and capital contributions to subsidiaries	(417,734		)	(539,575		)	(50,581		)
Purchase of investments	(12,518		)	(7,320		)	(21,915		)
Sales and maturities of investments	10,252			30,000			11,111
Acquisitions	(67,070		)	—			(1,773		)
Net cash used in investing activities	(487,070		)	(516,895		)	(63,158		)
Cash flows from financing activities:
Proceeds from borrowings	180,000			400,500			419,183
Payment of long term debt	(30,000		)	(215,000		)	(413,644		)
Proceeds from exercise of stock options	8,983			15,912			15,815
Proceeds from stock offering	15,225			—			—
Common stock repurchases	(19,779		)	(12,741		)	(7,809		)
Debt issue costs	(3,589		)	(3,623		)	(9,242		)
Contributions from noncontrolling interest	8,069			1,092			813
Purchase of noncontrolling interest	—			(14,429		)	—
Excess tax benefits from stock compensation	6,380			10,996			4,435
Net cash provided by financing activities	165,289			182,707			9,551
Net increase (decrease) in cash and cash equivalents	(19,539		)	(6,248		)	19,147
Cash and cash equivalents, beginning of period	22,279			28,527			9,380
Cash and cash equivalents, end of period	$	2,740		$	22,279		$	28,527
See notes to condensed financial information of registrant.
Notes to Condensed Financial Information of Registrant
Note A - Basis of Presentation and Significant Accounting Policies
The parent company only financial statements should be read in conjunction with Centene Corporation's audited consolidated financial statements and the notes to consolidated financial statements included in this Form 10-K.
The parent company's investment in subsidiaries is stated at cost plus equity in undistributed earnings of the subsidiaries. The parent company's share of net income of its unconsolidated subsidiaries is included in income using the equity method of accounting. Certain unrestricted subsidiaries receive monthly management fees from our restricted subsidiaries. The management and service fees received by our unrestricted subsidiaries are associated with all of the functions required to manage the restricted subsidiaries including but not limited to salaries and wages for all personnel, rent, utilities, medical management, provider contracting, compliance, member services, claims processing, information technology, cash management, finance and accounting, and other services. The management fees are based on a percentage of the restricted subsidiaries revenue.
Due to our centralized cash management function, all cash flows generated by our unrestricted subsidiaries, including management fees, are transferred to the parent company, primarily to repay borrowings on the parent company's revolving credit facility. The parent company may also utilize the cash flow to make acquisitions, fund capital contributions to subsidiaries and fund its operations. During the years ended December 31, 2013, 2012 and 2011, cash flows received by the parent from unrestricted subsidiaries was $312,887, $318,198, and $88,701 and was included in cash flows from operating activities.
Certain amounts presented in the parent company only financial statements are eliminated in the consolidated financial statements of Centene Corporation.
Note B - Dividends
During 2013, 2012 and 2011, the Registrant received dividends from its subsidiaries totaling $20,500, $29,000 and $69,100, respectively.

Basis_Of_Presentation_And_Sign

Basis Of Presentation And Significant Accounting Policies (Parent Company [Member])	12 Months Ended
	Dec. 31, 2013
Parent Company [Member]	'
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	'
	Note A - Basis of Presentation and Significant Accounting Policies
	The parent company only financial statements should be read in conjunction with Centene Corporation's audited consolidated financial statements and the notes to consolidated financial statements included in this Form 10-K.
	The parent company's investment in subsidiaries is stated at cost plus equity in undistributed earnings of the subsidiaries. The parent company's share of net income of its unconsolidated subsidiaries is included in income using the equity method of accounting. Certain unrestricted subsidiaries receive monthly management fees from our restricted subsidiaries. The management and service fees received by our unrestricted subsidiaries are associated with all of the functions required to manage the restricted subsidiaries including but not limited to salaries and wages for all personnel, rent, utilities, medical management, provider contracting, compliance, member services, claims processing, information technology, cash management, finance and accounting, and other services. The management fees are based on a percentage of the restricted subsidiaries revenue.
	Due to our centralized cash management function, all cash flows generated by our unrestricted subsidiaries, including management fees, are transferred to the parent company, primarily to repay borrowings on the parent company's revolving credit facility. The parent company may also utilize the cash flow to make acquisitions, fund capital contributions to subsidiaries and fund its operations. During the years ended December 31, 2013, 2012 and 2011, cash flows received by the parent from unrestricted subsidiaries was $312,887, $318,198, and $88,701 and was included in cash flows from operating activities.
	Certain amounts presented in the parent company only financial statements are eliminated in the consolidated financial statements of Centene Corporation.

Dividends

Dividends (Parent Company [Member])	12 Months Ended
	Dec. 31, 2013
Parent Company [Member]	'
Dividends Disclosure [Text Block]	'
	Note B - Dividends
	During 2013, 2012 and 2011, the Registrant received dividends from its subsidiaries totaling $20,500, $29,000 and $69,100, respectively.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Event	'
	Subsequent Events
	In January 2014, the Company acquired a majority interest in U.S. Medical Management, LLC, a management services organization and provider of in-home health services for high acuity populations, for approximately $200,000. The transaction consideration was financed through a combination of cash on hand and 2,243,217 shares of Centene common stock.

Summary_Of_Significant_Account1

Summary Of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]	'
Principles of Consolidation	'
	Principles of Consolidation
	The accompanying consolidated financial statements include the accounts of Centene Corporation and all majority owned subsidiaries and subsidiaries over which the Company exercises the power and control to direct activities significantly impacting financial performance. All material intercompany balances and transactions have been eliminated. The assets, liabilities and results of operations of Kentucky Spirit Health Plan are classified as discontinued operations for all periods presented.
	Certain amounts in the consolidated financial statements have been reclassified to conform to the 2013 presentation. These reclassifications have no effect on net earnings or stockholders' equity as previously reported.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with generally accepted accounting principles in the United States, or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Future events and their effects cannot be predicted with certainty; accordingly, the accounting estimates require the exercise of judgment. The accounting estimates used in the preparation of the consolidated financial statements will change as new events occur, as more experience is acquired, as additional information is obtained and as the operating environment changes. The Company evaluates and updates its assumptions and estimates on an ongoing basis and may employ outside experts to assist in our evaluation, as considered necessary. Actual results could differ from those estimates.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	Investments with original maturities of three months or less are considered to be cash equivalents. Cash equivalents consist of money market funds and bank certificates of deposit and savings accounts.
	The Company maintains amounts on deposit with various financial institutions, which may exceed federally insured limits. However, management periodically evaluates the credit-worthiness of those institutions, and the Company has not experienced any losses on such deposits.
Investments	'
	Investments
	Short term investments include securities with maturities greater than three months to one year. Long term investments include securities with maturities greater than one year.
	Short term and long term investments are generally classified as available for sale and are carried at fair value. Certain equity investments are recorded using the cost or equity method. Unrealized gains and losses on investments available for sale are excluded from earnings and reported in accumulated other comprehensive income, a separate component of stockholders' equity, net of income tax effects. Premiums and discounts are amortized or accreted over the life of the related security using the effective interest method. The Company monitors the difference between the cost and fair value of investments. Investments that experience a decline in value that is judged to be other than temporary are written down to fair value and a realized loss is recorded in investment and other income. To calculate realized gains and losses on the sale of investments, the Company uses the specific amortized cost of each investment sold. Realized gains and losses are recorded in investment and other income.
	The Company uses the equity method to account for certain of its investment in entities that it does not control and for which it does not have the ability to exercise significant influence over operating and financial policies. These investments are recorded at the lower of their cost or fair value.
Restricted Deposits	'
	Restricted Deposits
	Restricted deposits consist of investments required by various state statutes to be deposited or pledged to state agencies. These investments are classified as long term, regardless of the contractual maturity date, due to the nature of the states' requirements. The Company is required to annually adjust the amount of the deposit pledged to certain states.
Fair Value Measurements	'
	Fair Value Measurements
	In the normal course of business, the Company invests in various financial assets and incurs various financial liabilities. Fair values are disclosed for all financial instruments, whether or not such values are recognized in the Consolidated Balance Sheets. Management obtains quoted market prices and other observable inputs for these disclosures. The carrying amounts reported in the Consolidated Balance Sheets for cash and cash equivalents, premium and related receivables, unearned revenue, accounts payable and accrued expenses, and certain other current liabilities are carried at cost, which approximates fair value because of their short term nature.
	The following methods and assumptions were used to estimate the fair value of each financial instrument:
	•	Available for sale investments and restricted deposits: The carrying amount is stated at fair value, based on quoted market prices, where available. For securities not actively traded, fair values were estimated using values obtained from independent pricing services or quoted market prices of comparable instruments.
	•	Senior unsecured notes: Estimated based on third-party quoted market prices for the same or similar issues.
	•	Variable rate debt: The carrying amount of our floating rate debt approximates fair value since the interest rates adjust based on market rate adjustments.
	•	Interest rate swap: Estimated based on third-party market prices based on the forward 3-month LIBOR curve.
Property, Software and Equipment	'
	Property, Software and Equipment
	Property, software and equipment are stated at cost less accumulated depreciation. Capitalized software includes certain costs incurred in the development of internal-use software, including external direct costs of materials and services and payroll costs of employees devoted to specific software development. Depreciation is calculated principally by the straight-line method over estimated useful lives. Leasehold improvements are depreciated using the straight-line method over the shorter of the expected useful life or the remaining term of the lease. Property, software and equipment are depreciated over the following periods:
	Fixed Asset		Depreciation Period
	Buildings and land improvements		5 - 40 years
	Computer hardware and software		2 - 7 years
	Furniture and equipment		3 - 10 years
	Leasehold improvements		1 - 20 years
	The carrying amounts of all long-lived assets are evaluated to determine if adjustment to the depreciation and amortization period or to the unamortized balance is warranted. Such evaluation is based principally on the expected utilization of the long-lived assets.
	The Company retains fully depreciated assets in property and accumulated depreciation accounts until it removes them from service. In the case of sale, retirement, or disposal, the asset cost and related accumulated depreciation balance is removed from the respective account, and the resulting net amount, less any proceeds, is included as a component of earnings from operations in the consolidated statements of operations.
Goodwill and Intangible Assets	'
	Goodwill and Intangible Assets
	Intangible assets represent assets acquired in purchase transactions and consist primarily of customer relationships, purchased contract rights, provider contracts, trade names and goodwill. Intangible assets are amortized using the straight-line method over the following periods:
	Intangible Asset		Amortization Period
	Purchased contract rights		5 - 15 years
	Provider contracts		4 - 15 years
	Customer relationships		5 - 15 years
	Trade names		7 - 20 years
	The Company tests for impairment of intangible assets as well as long-lived assets whenever events or changes in circumstances indicate that the carrying value of an asset or asset group (hereinafter referred to as “asset group”) may not be recoverable by comparing the sum of the estimated undiscounted future cash flows expected to result from use of the asset group and its eventual disposition to the carrying value. Such factors include, but are not limited to, significant changes in membership, state funding, state contracts and provider networks and contracts. If the sum of the estimated undiscounted future cash flows is less than the carrying value, an impairment determination is required. The amount of impairment is calculated by subtracting the fair value of the asset group from the carrying value of the asset group. An impairment charge, if any, is recognized within earnings from operations.
	The Company tests goodwill for impairment using a fair value approach. The Company is required to test for impairment at least annually, absent a triggering event including a significant decline in operating performance that would require an impairment assessment. Absent any impairment indicators, the Company performs its goodwill impairment testing during the fourth quarter of each year. The Company recognizes an impairment charge for any amount by which the carrying amount of goodwill exceeds its implied fair value.
	The Company first assesses qualitative factors to determine whether it is necessary to perform the two-step quantitative goodwill impairment test. The Company does not calculate the fair value of a reporting unit unless it determines, based on a qualitative assessment, that it is more likely than not that its fair value is less than its carrying amount.
	If the two-step quantitative test is deemed necessary, the Company uses discounted cash flows to establish the fair value as of the testing date. The discounted cash flow approach includes many assumptions related to future growth rates, discount factors, future tax rates, etc. Changes in economic and operating conditions impacting these assumptions could result in goodwill impairment in future periods. When available and as appropriate, the Company uses comparative market multiples to corroborate discounted cash flow results.
Medical Claims Liability	'
	Medical Claims Liability
	Medical claims liability includes claims reported but not yet paid, or inventory, estimates for claims incurred but not reported, or IBNR, and estimates for the costs necessary to process unpaid claims at the end of each period.  The Company estimates its medical claims liability using actuarial methods that are commonly used by health insurance actuaries and meet Actuarial Standards of Practice.  These actuarial methods consider factors such as historical data for payment patterns, cost trends, product mix, seasonality, utilization of healthcare services and other relevant factors.
	Actuarial Standards of Practice generally require that the medical claims liability estimates be adequate to cover obligations under moderately adverse conditions.  Moderately adverse conditions are situations in which the actual claims are expected to be higher than the otherwise estimated value of such claims at the time of estimate.  In many situations, the claims amounts ultimately settled will be different than the estimate that satisfies the Actuarial Standards of Practice. The Company includes in its IBNR an estimate for medical claims liability under moderately adverse conditions which represents the risk of adverse deviation of the estimates in its actuarial method of reserving.
	The Company uses its judgment to determine the assumptions to be used in the calculation of the required estimates. The assumptions it considers when estimating IBNR include, without limitation, claims receipt and payment experience (and variations in that experience), changes in membership, provider billing practices, healthcare service utilization trends, cost trends, product mix, seasonality, prior authorization of medical services, benefit changes, known outbreaks of disease or increased incidence of illness such as influenza, provider contract changes, changes to fee schedules, and the incidence of high dollar or catastrophic claims.
	The Company's development of the medical claims liability estimate is a continuous process which it monitors and refines on a monthly basis as additional claims receipts and payment information becomes available. As more complete claims information becomes available, the Company adjusts the amount of the estimates, and includes the changes in estimates in medical costs in the period in which the changes are identified. In every reporting period, the operating results include the effects of more completely developed medical claims liability estimates associated with previously reported periods. The Company consistently applies its reserving methodology from period to period. As additional information becomes known, it adjusts the actuarial model accordingly to establish medical claims liability estimates.
	The Company periodically reviews actual and anticipated experience compared to the assumptions used to establish medical costs. The Company establishes premium deficiency reserves if actual and anticipated experience indicates that existing policy liabilities together with the present value of future gross premiums will not be sufficient to cover the present value of future benefits, settlement and maintenance costs.
Revenue Recognition	'
	Revenue Recognition
	The Company's health plans generate revenues primarily from premiums received from the states in which it operates health plans. The Company receives a fixed premium per member per month pursuant to its state contracts. The Company generally receives premium payments during the month it provides services and recognizes premium revenue during the period in which it is obligated to provide services to its members. In some instances, the Company's base premiums are subject to an adjustment, or risk score, based on the acuity of its membership. Generally, the risk score is determined by the State analyzing submissions of processed claims data to determine the acuity of the Company's membership relative to the entire state's Medicaid membership. Some states enact premium taxes, similar assessments and provider pass-through payments, collectively premium taxes, and these taxes are recorded as a separate component of both revenues and operating expenses. Some contracts allow for additional premiums related to certain supplemental services provided such as maternity deliveries.
	Revenues are recorded based on membership and eligibility data provided by the states, which is adjusted on a monthly basis by the states for retroactive additions or deletions to membership data. These eligibility adjustments are estimated monthly and subsequent adjustments are made in the period known. We continuously review and update those estimates as new information becomes available.  It is possible that new information could require us to make additional adjustments, which could be significant, to these estimates.
	The Company's specialty companies generate revenues under contracts with state programs, individuals, healthcare organizations and other commercial organizations, as well as from the Company's own subsidiaries. Revenues are recognized when the related services are provided or as ratably earned over the covered period of service.
Premium And Related Receivables And Unearned Revenue	'
	Premium and Related Receivables and Unearned Revenue
	Premium and service revenues collected in advance are recorded as unearned revenue. For performance-based contracts the Company does not recognize revenue subject to refund until data is sufficient to measure performance. Premiums and service revenues due to the Company are recorded as premium and related receivables and are recorded net of an allowance based on historical trends and management's judgment on the collectibility of these accounts. As the Company generally receives payments during the month in which services are provided, the allowance is typically not significant in comparison to total revenues and does not have a material impact on the presentation of the financial condition or results of operations. Activity in the allowance for uncollectible accounts for the years ended December 31, is summarized below:
		2013			2012			2011
	Allowances, beginning of year	781			639			17
	Amounts charged to expense	3,138			1,350			865
	Write-offs of uncollectible receivables	(2,801	)		(1,208	)		(243	)
	Allowances, end of year	1,118			781			639
Significant Customers	'
	Significant Customers
	Centene receives the majority of its revenues under contracts or subcontracts with state Medicaid managed care programs. The current contracts expire on various dates between March 31, 2014 and October 31, 2018. States whose aggregate annual contract value exceeded 10% of annual revenues and the respective percentage of the Company's total revenues for the years ended December 31, are as follows:
	2013			2012			2011
	Texas	37%		Texas	40%		Georgia	15%
							Ohio	12%
							Texas	21%
Reinsurance	'
	Reinsurance
	Centene's subsidiaries report reinsurance premiums as medical costs, while related reinsurance recoveries are reported as deductions from medical costs. The Company limits its risk of certain catastrophic losses by maintaining high deductible reinsurance coverage.
Other Income (Expense)	'
	Other Income (Expense)
	Other income (expense) consists principally of investment income, interest expense and equity method earnings from investments. Investment income is derived from the Company's cash, cash equivalents, restricted deposits and investments. Interest expense relates to borrowings under the senior notes, interest rate swap, credit facilities, interest on capital leases and credit facility fees.
Income Taxes	'
	Income Taxes
	Deferred tax assets and liabilities are recorded for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax law or tax rates is recognized in income in the period that includes the enactment date.
	Valuation allowances are provided when it is considered more likely than not that deferred tax assets will not be realized. In determining if a deductible temporary difference or net operating loss can be realized, the Company considers future reversals of existing taxable temporary differences, future taxable income, taxable income in prior carryback periods and tax planning strategies.
Contingencies	'
	Contingencies
	The Company accrues for loss contingencies associated with outstanding litigation, claims and assessments for which it has determined it is probable that a loss contingency exists and the amount of loss can be reasonably estimated. The Company expenses professional fees associated with litigation claims and assessments as incurred.
Stock Based Compensation	'
	Stock Based Compensation
	The fair value of the Company's employee share options and similar instruments are estimated using the Black-Scholes option-pricing model. That cost is recognized over the period during which an employee is required to provide service in exchange for the award. Excess tax benefits related to stock compensation are presented as a cash inflow from financing activities.

Summary_Of_Significant_Account2

Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]	'
Schedule Of Property Software And Equipment Depreciation Periods [Table Text Block]	'
	Property, software and equipment are depreciated over the following periods:
	Fixed Asset		Depreciation Period
	Buildings and land improvements		5 - 40 years
	Computer hardware and software		2 - 7 years
	Furniture and equipment		3 - 10 years
	Leasehold improvements		1 - 20 years
Schedule Of Amortization Period For Intangible Assets [Table Text Block]	'
	Intangible assets are amortized using the straight-line method over the following periods:
	Intangible Asset		Amortization Period
	Purchased contract rights		5 - 15 years
	Provider contracts		4 - 15 years
	Customer relationships		5 - 15 years
	Trade names		7 - 20 years
Schedule Of Allowance For Uncollectible Accounts [Table Text Block]	'
	Activity in the allowance for uncollectible accounts for the years ended December 31, is summarized below:
		2013			2012			2011
	Allowances, beginning of year	781			639			17
	Amounts charged to expense	3,138			1,350			865
	Write-offs of uncollectible receivables	(2,801	)		(1,208	)		(243	)
	Allowances, end of year	1,118			781			639
Schedule Of Percentage Of Company's Total Revenue [Table Text Block]	'
	States whose aggregate annual contract value exceeded 10% of annual revenues and the respective percentage of the Company's total revenues for the years ended December 31, are as follows:
	2013			2012			2011
	Texas	37%		Texas	40%		Georgia	15%
							Ohio	12%
							Texas	21%

Noncontolling_Interest_and_Acq1

Noncontolling Interest and Acquisitions Non Controlling Interest and Acquisition (Tables)	12 Months Ended
	Dec. 31, 2013
Noncontrolling Interest [Abstract]	'
Noncontrolling Interest Disclosure [Text Block]	'
	The Company has consolidated subsidiaries where it maintains less than 100% ownership.  The Company’s ownership interest for each subsidiary as of December 31, are as follows:
			2013		2012			2011
	Casenet		100	%	100	%		81	%
	Centurion		51	%	51	%		51	%
	Louisiana Healthcare Connections		100	%	100	%		51	%
	Home State Health Plan		95	%	95	%		—	%
Schedule of Net Income Atrributable to Parent and Transfers from and to Non-controlling Interest Entities	'
	Net income attributable to Centene Corporation and transfers from (to) noncontrolling interest entities are as follows:
		Year Ended December 31,
		2013			2012				2011
	Net earnings attributable to Centene Corporation	$	161,218		$	88,533			$	120,518
	Transfers from (to) the noncontrolling interest:
	Decrease in equity for purchase of, distribution to and redemption of noncontrolling interest	—			(12,193		)		(289		)
	Increase in equity for distributions from and consolidation of noncontrolling interest	8,068			1,092				813
	Net transfers from (to) noncontrolling interest	8,068			(11,101		)		524
	Changes from net earnings attributable to Centene Corporation and net transfers from (to) the noncontrolling interest	$	169,286		$	77,432			$	121,042

Discontinued_Operations_Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Schedule of Restructuring Reserve by Type of Cost [Table Text Block]	'
	During the years ended December 31, 2013 and 2012, the Company incurred exit costs consisting primarily of lease termination fees and employee severance. The change in exit cost liability for KSHP is summarized as follows:
		Employee Benefits			Lease Termination			Total
	Balance, December 31, 2011	$	—		$	—		$	—
	Incurred	2,939			—			2,939
	Balance, December 31, 2012	2,939			—			2,939
	Incurred	434			735			1,169
	Paid	(2,837		)	—			(2,837		)
	Balance, December 31, 2013	$	536		$	735		$	1,271
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	'
	Assets and liabilities of the discontinued operations are as follows:
		December 31, 2013			December 31, 2012
	Current assets	$	77,512		$	176,996
	Long term investments and restricted deposits	38,305			60,461
	Other assets	—			1,836
	Assets of discontinued operations	$	115,817		$	239,293
	Medical claims liability	$	27,637		$	111,141
	Accounts payable and accrued expenses	2,657			45,975
	Other liabilities	1,028			357
	Liabilities of discontinued operations	$	31,322		$	157,473
	Operating results for the discontinued operations are as follows:
		Year Ended December 31,
		2013			2012			2011
	Revenues	$	248,327		$	557,316		$	129,105
	Earnings (loss) before income taxes	$	6,165		$	(134,415	)	$	(13,465	)
	Net earnings (loss)	$	3,881		$	(86,674	)	$	(9,300	)

ShortTerm_And_LongTerm_Investm1

Short-Term And Long-Term Investments And Restricted Deposits (Tables)	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Short-Term And Long-Term Investments And Restricted Deposits By Investment Type	'
	Short term and long term investments and restricted deposits by investment type consist of the following:
		December 31, 2013										December 31, 2012
		Amortized			Gross		Gross			Fair		Amortized			Gross		Gross			Fair
		Cost			Unrealized		Unrealized Losses			Value		Cost			Unrealized		Unrealized Losses			Value
					Gains										Gains
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	246,085		$	245	$	(7,494	)	$	238,836	$	110,941		$	581	$	(221	)	$	111,301
	Corporate securities	293,912			2,782		(608		)	296,086		290,691			4,615		(195		)	295,111
	Restricted certificates of deposit	5,891			—		—			5,891		5,890			—		—			5,890
	Restricted cash equivalents	26,642			—		—			26,642		14,455			—		—			14,455
	Municipal securities:
	General obligation	54,003			555		(136		)	54,422		85,440			1,157		(26		)	86,571
	Pre-refunded	10,835			82		—			10,917		5,337			85		—			5,422
	Revenue	68,801			545		(292		)	69,054		82,781			1,313		(30		)	84,064
	Variable rate demand notes	28,575			—		—			28,575		23,385			—		—			23,385
	Asset backed securities	138,803			579		(332		)	139,050		73,570			1,082		(15		)	74,637
	Mortgage backed securities	33,974			—		(83		)	33,891		—			—		—			—
	Cost and equity method investments	22,239			—		—			22,239		11,298			—		—			11,298
	Life insurance contracts	15,369			—		—			15,369		15,023			—		—			15,023
	Total	$	945,129		$	4,788	$	(8,945	)	$	940,972	$	718,811		$	8,833	$	(487	)	$	727,157
Schedule Of Available-For-Sale Investments In A Continuous Unrealized Loss Position	'
	The fair value of available-for-sale investments with gross unrealized losses by investment type and length of time that individual securities have been in a continuous unrealized loss position were as follows:
		December 31, 2013										December 31, 2012
		Less Than 12 Months					12 Months or More					Less Than 12 Months					12 Months or More
		Unrealized Losses			Fair		Unrealized Losses			Fair		Unrealized Losses			Fair		Unrealized Losses			Fair
					Value					Value					Value					Value
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	(6,188	)	$	172,365	$	(1,307	)	$	26,454	$	(219	)	$	56,033	$	(2	)	$	201
	Corporate securities	(400		)	52,725		(207		)	5,020		(195		)	44,208		—			—
	Municipal securities:
	General obligation	(72		)	3,480		(63		)	2,426		(26		)	7,930		—			—
	Revenue	(292		)	27,789		—			—		(30		)	3,090		—			—
	Asset backed securities	(333		)	37,689		—			—		(15		)	8,192		—			—
	Mortgage backed securities	(83		)	33,891		—			—		—			—		—			—
	Total	$	(7,368	)	$	327,939	$	(1,577	)	$	33,900	$	(485	)	$	119,453	$	(2	)	$	201
Contractual Maturities Of Short-Term And Long-Term Investments And Restricted Deposits	'
	The contractual maturities of short term and long term investments and restricted deposits are as follows:
		December 31, 2013										December 31, 2012
		Investments					Restricted Deposits					Investments					Restricted Deposits
		Amortized			Fair		Amortized			Fair		Amortized			Fair		Amortized			Fair
		Cost			Value		Cost			Value		Cost			Value		Cost			Value
	One year or less	$	101,537		$	102,126	$	40,633		$	40,637	$	136,997		$	138,101	$	33,897		$	33,928
	One year through five years	609,755			610,589		6,301			6,309		429,053			435,728		358			358
	Five years through ten years	157,003			151,221		—			—		93,907			93,778		—			—
	Greater than ten years	29,900			30,090		—			—		24,599			25,264		—			—
	Total	$	898,195		$	894,026	$	46,934		$	46,946	$	684,556		$	692,871	$	34,255		$	34,286

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements By Level For Assets Measured At Fair Value On A Recurring Basis	'
	The following table summarizes fair value measurements by level at December 31, 2013, for assets and liabilities measured at fair value on a recurring basis:
		Level I		Level II		Level III		Total
	Assets
	Cash and cash equivalents	$	974,304	$	—	$	—	$	974,304
	Investments available for sale:
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	212,185	$	12,238	$	—	$	224,423
	Corporate securities	—		296,086		—		296,086
	Municipal securities:
	General obligation	—		54,422		—		54,422
	Pre-refunded	—		10,917		—		10,917
	Revenue	—		69,054		—		69,054
	Variable rate demand notes	—		28,575		—		28,575
	Asset backed securities	—		139,050		—		139,050
	Mortgage backed securities	$	—	$	33,891	$	—	$	33,891
	Total investments	$	212,185	$	644,233	$	—	$	856,418
	Restricted deposits available for sale:
	Cash and cash equivalents	$	26,642	$	—	$	—	$	26,642
	Certificates of deposit	5,891		—		—		5,891
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	14,413		—		—		14,413
	Total restricted deposits	$	46,946	$	—	$	—	$	46,946
	Other long term assets:
	Interest rate swap contract	$	—	$	9,576	$	—	$	9,576
	Total assets at fair value	$	1,233,435	$	653,809	$	—	$	1,887,244
	The following table summarizes fair value measurements by level at December 31, 2012, for assets and liabilities measured at fair value on a recurring basis:
		Level I		Level II		Level III		Total
	Assets
	Cash and cash equivalents	$	745,933	$	—	$	—	$	745,933
	Investments available for sale:
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	57,114	$	40,246	$	—	$	97,360
	Corporate securities	—		295,111		—		295,111
	Municipal securities:
	General obligation	—		86,571		—		86,571
	Pre-refunded	—		5,422		—		5,422
	Revenue	—		84,064		—		84,064
	Variable rate demand notes	—		23,385		—		23,385
	Asset backed securities	—		74,637		—		74,637
	Mortgage backed securities	—		—		—		—
	Total investments	$	57,114	$	609,436	$	—	$	666,550
	Restricted deposits available for sale:
	Cash and cash equivalents	$	14,455	$	—	$	—	$	14,455
	Certificates of deposit	5,890		—		—		5,890
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	13,941		—		—		13,941
	Total restricted deposits	$	34,286	$	—	$	—	$	34,286
	Other long term assets:
	Interest rate swap contract	$	—	$	16,304	$	—	$	16,304
	Total assets at fair value	$	837,333	$	625,740	$	—	$	1,463,073

Property_Software_And_Equipmen1

Property, Software And Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property, Software and Equipment [Abstract]	'
Property, Software and Equipment	'
	Property, software and equipment consist of the following as of December 31:
		2013			2012
	Computer software	$	184,983		$	164,755
	Building	206,058			193,186
	Land	69,705			70,276
	Computer hardware	69,087			57,389
	Furniture and office equipment	53,180			43,136
	Leasehold improvements	56,816			49,808
		639,829			578,550
	Less accumulated depreciation	(244,422		)	(202,657		)
	Property, software and equipment, net	$	395,407		$	375,893

Goodwill_And_Intangible_Assets1

Goodwill And Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets [Abstract]	'
Schedule Of Changes In Goodwill By Operating Segment	'
	The following table summarizes the changes in goodwill by operating segment:
		Managed Care			Specialty Services			Total
	Balance as of December 31, 2011	$	151,402		$	130,579		$	281,981
	Impairment	—			(25,693		)	(25,693		)
	Balance as of December 31, 2012	151,402			104,886			256,288
	Acquisition	—			92,144			92,144
	Balance as of December 31, 2013	$	151,402		$	197,030		$	348,432
Schedule Of Intangible Assets	'
	Intangible assets at December 31, consist of the following:
								Weighted Average Life in Years
		2013			2012			2013		2012
	Purchased contract rights	$	21,988		$	21,988		7.5		7.5
	Provider contracts	35,537			2,737			13.2		9.8
	Customer relationships	13,396			13,396			8		8
	Trade names	8,695			6,495			18.9		16.3
	Intangible assets	79,616			44,616			11.1		9.1
	Less accumulated amortization:
	Purchased contract rights	(13,459		)	(11,010		)
	Provider contracts	(3,767		)	(1,241		)
	Customer relationships	(11,425		)	(10,214		)
	Trade names	(2,185		)	(1,883		)
	Total accumulated amortization	(30,836		)	(24,348		)
	Intangible assets, net	$	48,780		$	20,268
Schedule Of Future Amortization Expenses	'
	Estimated total amortization expense related to intangible assets for each of the five succeeding fiscal years is as follows:
	Year		Expense
	2014		$	6,800
	2015		5,900
	2016		5,900
	2017		4,400
	2018		2,600

Medical_Claims_Liability_Table

Medical Claims Liability (Tables)	12 Months Ended
	Dec. 31, 2013
Medical Claims Liability [Abstract]	'
Schedule Of Change In Medical Claims Liability	'
	The change in medical claims liability is summarized as follows:
		Year Ended December 31,
		2013			2012			2011
	Balance, January 1,	$	815,161		$	518,840		$	456,765
	Incurred related to:
	Current year	9,072,867			6,836,177			4,256,645
	Prior years	(78,226		)	(55,096		)	(65,377		)
	Total incurred	8,994,641			6,781,081			4,191,268
	Paid related to:
	Current year	7,975,367			6,024,720			3,744,475
	Prior years	722,726			460,040			384,718
	Total paid	8,698,093			6,484,760			4,129,193
	Balance, December 31,	$	1,111,709		$	815,161		$	518,840

Debt_Tables

Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Schedule Of Debt	'
	Debt consists of the following:
		December 31, 2013			December 31, 2012
	Senior notes, at par	$	425,000		$	425,000
	Unamortized premium on senior notes	6,052			7,823
	Interest rate swap fair value	9,576			16,304
	Senior notes	440,628			449,127
	Revolving credit agreement	150,000			—
	Mortgage notes payable	72,785			84,081
	Capital leases and other	5,349			5,646
	Total debt	668,762			538,854
	Less current portion	(3,065		)	(3,373		)
	Long term debt	$	665,697		$	535,481
Schedule Of Aggregate Maturities Of Debt	'
	Aggregate maturities for the Company's debt are as follows:
	2014		$	3,065
	2015		3,188
	2016		3,353
	2017		428,525
	2018		153,702
	Thereafter		61,301
	Total		$	653,134

Income_Taxes_Income_Taxes_Tabl

Income Taxes Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Taxes [Abstract]	'
Consolidated Income Tax Expense	'
	The consolidated income tax expense consists of the following for the years ended December 31:
		2013			2012			2011
	Current provision:
	Federal	$	120,858		$	47,528		$	63,388
	State and local	5,857			(4,368		)	5,157
	Total current provision	126,715			43,160			68,545
	Deferred provision	(19,635		)	4,252			2,142
	Total provision for income taxes	$	107,080		$	47,412		$	70,687
Reconciliation Of The Tax Provision At The U.S. Federal Statutory Rate To The Provision For Income Taxes	'
	The reconciliation of the tax provision at the U.S. Federal Statutory Rate to the provision for income taxes is as follows:
		2013			2012			2011
	Earnings from continuing operations, before income tax expense	$	268,917		$	122,791		$	188,350
	Less flow through noncontrolling interest	960			(2,539		)	(2,855		)
	Earnings from continuing operations, less noncontrolling interest, before income tax expense	267,957			125,330			191,205
	Tax provision at the U.S. federal statutory rate	93,785			43,866			66,922
	State income taxes, net of federal income tax benefit	2,871			(2,288		)	3,381
	Nondeductible goodwill impairment	—			8,487			—
	Nondeductible compensation	12,519			1,108			2,705
	Other, net	(2,095		)	(3,761		)	(2,321		)
	Income tax expense	$	107,080		$	47,412		$	70,687
Tax Effects Of Temporary Differences Which Give Rise To Deferred Tax Assets And Liabilities	'
	The tax effects of temporary differences which give rise to deferred tax assets and liabilities are presented below for the years ended December 31:
		2013			2012
	Deferred tax assets:
	Medical claims liability and other accruals	$	53,943		$	37,413
	State net operating loss carry forward	9,530			9,055
	Stock compensation	14,223			12,615
	Other	30,199			20,573
	Deferred tax assets	107,895			79,656
	Valuation allowance	(8,119		)	(8,180		)
	Net deferred tax assets	$	99,776		$	71,476
	Deferred tax liabilities:
	Intangible assets	$	18,278		$	12,441
	Prepaid assets	5,621			4,767
	Depreciation and amortization	30,411			31,741
	Other	1,615			5,624
	Deferred tax liabilities	$	55,925		$	54,573
	Net deferred tax assets	$	43,851		$	16,903
Reserve For Uncertain Tax Positions	'
	The Company maintains a reserve for uncertain tax positions that may be challenged by a tax authority. A roll-forward of the reserve is as follows:
		2013			2012
	Gross unrecognized tax benefits, beginning of period	$	7,870		$	13,552
	Gross increases:
	Current year tax positions	338			4,107
	Prior year tax positions	164			451
	Gross decreases:
	Prior year tax positions	—			(9,925		)
	Settlements	(4,390		)	(53		)
	Statute of limitation lapses	(708		)	(262		)
	Gross unrecognized tax benefits, end of period	$	3,274		$	7,870

Stock_Incentive_Plans_Tables

Stock Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2013
Stock Incentive Plans [Abstract]	'
Summary Of Stock Option Activity	'
	Option activity for the year ended December 31, 2013 is summarized below:
		Shares			Weighted Average Exercise Price			Aggregate Intrinsic Value			Weighted Average Remaining Contractual Term
	Outstanding as of December 31, 2012	1,299,396			$	22.39
	Granted	10,000			44.58
	Exercised	(361,538	)		20.32
	Forfeited	(663	)		17.86
	Outstanding as of December 31, 2013	947,195			$	23.41		$	33,659		2.8
	Exercisable as of December 31, 2013	921,462			$	23.21		$	32,937		2.7
Option Pricing Assumptions	'
	The fair value of each option grant is estimated on the date of the grant using the Black-Scholes option-pricing model with the following weighted-average assumptions:
		Year Ended December 31,
		2013		2012 (1)		2011
	Expected life (in years)	5.1		—		5.2
	Risk-free interest rate	0.80%		—		0.90%
	Expected volatility	48.10%		—		49.90%
	Expected dividend yield	—		—		—
	(1) No options were awarded in the year ended December 31, 2012.
Stock Option Awards	'
	Other information pertaining to option activity is as follows:
		Year Ended December 31,
		2013				2012 (1)			2011
	Weighted-average fair value of options granted	$	19.04			$	—		$	13.94
	Total intrinsic value of stock options exercised	$	12,845			$	24,120		$	11,744
	(1) No options were awarded in the year ended December 31, 2012.
Non-Vested Restricted Stock And Restricted Stock	'
	A summary of the Company's non-vested restricted stock and restricted stock unit shares as of December 31, 2013, and changes during the year ended December 31, 2013, is presented below:
		Shares			Weighted Average Grant Date Fair Value
	Non-vested balance as of December 31, 2012	2,058,908			$	37.25
	Granted	1,037,542			55.36
	Vested	(961,741	)		33.57
	Forfeited	(45,116	)		38.91
	Non-vested balance as of December 31, 2013	2,089,593			$	47.9

Commitments_Tables

Commitments (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments [Abstract]	'
Annual Non-Cancelable Minimum Lease Payments	'
	Annual non-cancelable minimum lease payments over the next five years and thereafter are as follows:
	2014	$	25,350
	2015	25,871
	2016	24,202
	2017	19,336
	2018	12,628
	Thereafter	18,800
		$	126,187

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Calculation Of Basic And Diluted Net Earnings Per Common Share	'
	The following table sets forth the calculation of basic and diluted net earnings per common share for the years ended December 31:
		2013		2012			2011
	Earnings attributable to Centene Corporation:
	Earnings from continuing operations, net of tax	$	161,218	$	88,533		$	120,518
	Discontinued operations, net of tax	3,881		(86,674		)	(9,300		)
	Net earnings	$	165,099	$	1,859		$	111,218
	Shares used in computing per share amounts:
	Weighted average number of common shares outstanding	54,126,545		51,509,366			50,198,954
	Common stock equivalents (as determined by applying the treasury stock method)	2,120,628		2,205,009			2,275,284
	Weighted average number of common shares and potential dilutive common shares outstanding	56,247,173		53,714,375			52,474,238
	Net earnings per common share attributable to Centene Corporation:
	Basic:
	Continuing operations	$	2.98	$	1.72		$	2.4
	Discontinued operations	0.07		(1.68		)	(0.18		)
	Basic earnings per common share	$	3.05	$	0.04		$	2.22
	Diluted:
	Continuing operations	$	2.87	$	1.65		$	2.3
	Discontinued operations	0.07		(1.62		)	(0.18		)
	Diluted earnings per common share	$	2.94	$	0.03		$	2.12

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	Segment information as of and for the year ended December 31, 2013, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	9,740,720	$	785,320	$	—		$	10,526,040
	Premium and service revenues from internal customers	41,094		2,147,200		(2,188,294		)	—
	Total premium and service revenues	9,781,814		2,932,520		(2,188,294		)	10,526,040
	Earnings from operations	197,844		79,573		—			277,417
	Total assets	2,817,519		595,964		—			3,413,483
	Segment information as of and for the year ended December 31, 2012, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	7,124,720	$	556,911	$	—		$	7,681,631
	Premium and service revenues from internal customers	87,319		1,550,096		(1,637,415		)	—
	Total premium and service revenues	7,212,039		2,107,007		(1,637,415		)	7,681,631
	Earnings from operations	62,867		45,099		—			107,966
	Total assets	2,163,347		371,265		—			2,534,612
	Segment information as of and for the year ended December 31, 2011, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	4,571,430	$	480,472	$	—		$	5,051,902
	Premium and service revenues from internal customers	64,809		710,002		(774,811		)	—
	Total premium and service revenues	4,636,239		1,190,474		(774,811		)	5,051,902
	Earnings from operations	161,890		41,913		—			203,803
	Total assets	1,709,271		383,259		—			2,092,530

Quarterly_Selected_Financial_I1

Quarterly Selected Financial Information (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Selected Financial Information [Abstract]	'
Quarterly Selected Financial Information	'
		For the Quarter Ended
		March 31,			June 30,			September 30,			December 31,
		2013			2013			2013			2013
	Total revenues	$	2,525,482		$	2,610,538		$	2,795,569		$	2,931,740
	Amounts attributable to Centene Corporation common shareholders:
	Earnings from continuing operations, net of income tax expense	$	22,639		$	40,289		$	50,325		$	47,965
	Discontinued operations, net of income tax expense (benefit)	363			(805		)	(952		)	5,275
	Net earnings	$	23,002		$	39,484		$	49,373		$	53,240
	Net earnings (loss) per common share attributable to Centene Corporation:
	Basic:
	Continuing operations	$	0.43		$	0.74		$	0.92		$	0.87
	Discontinued operations	0.01			(0.02		)	(0.02		)	0.1
	Basic earnings per common share	$	0.44		$	0.72		$	0.9		$	0.97
	Diluted:
	Continuing operations	$	0.41		$	0.71		$	0.88		$	0.84
	Discontinued operations	0.01			0.01			(0.01		)	0.09
	Diluted earnings per common share	$	0.42		$	0.72		$	0.87		$	0.93
	Health Benefits Ratio	90.2		%	88.4		%	87.8		%	88.1		%
	General & Administrative Expense Ratio	8.4		%	8.9		%	9.1		%	8.9		%
	Period end at-risk membership	2,553,400			2,563,400			2,612,500			2,723,200
		For the Quarter Ended
		March 31,			June 30,			September 30,			December 31,
		2012			2012			2012			2012
	Total revenues	$	1,562,809		$	1,967,362		$	2,308,075		$	2,272,050
	Amounts attributable to Centene Corporation common shareholders:
	Earnings (loss) from continuing operations, net of income tax expense (benefit)	$	27,072		$	(16,656	)	$	59,438		$	18,679
	Discontinued operations, net of income tax benefit	(3,094		)	(18,343		)	(55,619		)	(9,618		)
	Net earnings (loss)	$	23,978		$	(34,999	)	$	3,819		$	9,061
	Net earnings (loss) per common share attributable to Centene Corporation:
	Basic:
	Continuing operations	$	0.53		$	(0.32	)	$	1.15		$	0.36
	Discontinued operations	(0.06		)	(0.36		)	(1.08		)	(0.19		)
	Basic earnings per common share	$	0.47		$	(0.68	)	$	0.07		$	0.17
	Diluted:
	Continuing operations	$	0.51		$	(0.32	)	$	1.1		$	0.35
	Discontinued operations	(0.06		)	(0.36		)	(1.03		)	(0.18		)
	Diluted earnings per common share	$	0.45		$	(0.68	)	$	0.07		$	0.17
	Health Benefits Ratio	87.1		%	91.2		%	88.7		%	90.7		%
	General & Administrative Expense Ratio	10.4		%	8.5		%	8.4		%	8.4		%
	Period end at-risk membership	2,003,800			2,254,000			2,357,600			2,424,500

Condensed_Financial_Informatio1

Condensed Financial Information Of Registrant (Tables) (Parent Company [Member])	12 Months Ended
	Dec. 31, 2013
Parent Company [Member]	'
Condensed Balance Sheets	'
	Centene Corporation (Parent Company Only)
	Condensed Balance Sheets
	(In thousands, except share data)
		December 31,
		2013			2012
	ASSETS
	Current assets:
	Cash and cash equivalents	$	2,740		$	22,279
	Short term investments, at fair value (amortized cost $6,000 and $6,500, respectively)	6,000			6,500
	Other current assets	124,903			42,230
	Total current assets	133,643			71,009
	Long term investments, at fair value (amortized cost $8,070 and $1,356, respectively)	8,070			1,356
	Investment in subsidiaries	1,667,258			1,298,648
	Other long term assets	31,876			42,523
	Total assets	$	1,840,847		$	1,413,536
	LIABILITIES AND STOCKHOLDERS' EQUITY
	Current liabilities	$	4,460		$	4,333
	Long term debt	590,628			449,127
	Other long term liabilities	2,320			6,309
	Total liabilities	597,408			459,769
	Stockholders' equity:
	Common stock, $.001 par value; authorized 100,000,000 shares; 58,673,215 issued and 55,319,239 outstanding at December 31, 2013, and 55,339,160 issued and 52,329,248 outstanding at December 31, 2012	59			55
	Additional paid-in capital	594,326			450,856
	Accumulated other comprehensive income:
	Unrealized gain (loss) on investments, net of tax	(2,620		)	5,189
	Retained earnings	731,919			566,820
	Treasury stock, at cost (3,353,976 and 3,009,912 shares, respectively)	(89,643		)	(69,864		)
	Total Centene stockholders' equity	1,234,041			953,056
	Noncontrolling interest	9,398			711
	Total stockholders' equity	1,243,439			953,767
	Total liabilities and stockholders' equity	$	1,840,847		$	1,413,536
Condensed Statements Of Operations	'
	Centene Corporation (Parent Company Only)
	Condensed Statements of Operations
	(In thousands, except share data)
		Year Ended December 31,
		2013			2012			2011
	Expenses:
	General and administrative expenses	$	4,196		$	4,090		$	4,488
	Other income (expense):
	Investment and other income	983			19,921			(8,790		)
	Interest expense	(22,623		)	(15,757		)	(15,494		)
	Earnings (loss) before income taxes	(25,836		)	74			(28,772		)
	Income tax benefit	(15,191		)	(9,668		)	(12,825		)
	Net earnings (loss) before equity in subsidiaries	(10,645		)	9,742			(15,947		)
	Equity in earnings from subsidiaries	171,863			78,791			136,465
	Net earnings from continuing operations	$	161,218		$	88,533		$	120,518
	Net earnings per share from continuing operations:
	Basic earnings per common share	$	2.98		$	1.72		$	2.4
	Diluted earnings per common share	$	2.87		$	1.65		$	2.3
	Weighted average number of shares outstanding:
	Basic	54,126,545			51,509,366			50,198,954
	Diluted	56,247,173			53,714,375			52,474,238
Condensed Statements Of Cash Flows	'
	Centene Corporation (Parent Company Only)
	Condensed Statements of Cash Flows
	(In thousands)
		Year Ended December 31,
		2013			2012			2011
	Cash flows from operating activities:
	Cash provided by operating activities	$	302,242		$	327,940		$	72,754
	Cash flows from investing activities:
	Net dividends from and capital contributions to subsidiaries	(417,734		)	(539,575		)	(50,581		)
	Purchase of investments	(12,518		)	(7,320		)	(21,915		)
	Sales and maturities of investments	10,252			30,000			11,111
	Acquisitions	(67,070		)	—			(1,773		)
	Net cash used in investing activities	(487,070		)	(516,895		)	(63,158		)
	Cash flows from financing activities:
	Proceeds from borrowings	180,000			400,500			419,183
	Payment of long term debt	(30,000		)	(215,000		)	(413,644		)
	Proceeds from exercise of stock options	8,983			15,912			15,815
	Proceeds from stock offering	15,225			—			—
	Common stock repurchases	(19,779		)	(12,741		)	(7,809		)
	Debt issue costs	(3,589		)	(3,623		)	(9,242		)
	Contributions from noncontrolling interest	8,069			1,092			813
	Purchase of noncontrolling interest	—			(14,429		)	—
	Excess tax benefits from stock compensation	6,380			10,996			4,435
	Net cash provided by financing activities	165,289			182,707			9,551
	Net increase (decrease) in cash and cash equivalents	(19,539		)	(6,248		)	19,147
	Cash and cash equivalents, beginning of period	22,279			28,527			9,380
	Cash and cash equivalents, end of period	$	2,740		$	22,279		$	28,527

Organization_And_Operations_De

Organization And Operations (Details)	12 Months Ended
	Dec. 31, 2013
	segments
Organization And Operations [Abstract]	'
Number of reportable segments	2

Summary_Of_Significant_Account3

Summary Of Significant Accounting Policies (Schedule Of Property, Software And Equipment Depreciation Periods) (Details)	12 Months Ended
	Dec. 31, 2013
Minimum [Member] | Buildings And Land Improvements [Member]	'
Property, Plant and Equipment [Line Items]	'
Fixed Asset - Depreciation Period	'5 years
Minimum [Member] | Computer Hardware And Software [Member]	'
Property, Plant and Equipment [Line Items]	'
Fixed Asset - Depreciation Period	'2 years
Minimum [Member] | Furniture And Equipment [Member]	'
Property, Plant and Equipment [Line Items]	'
Fixed Asset - Depreciation Period	'3 years
Minimum [Member] | Leasehold Improvements [Member]	'
Property, Plant and Equipment [Line Items]	'
Fixed Asset - Depreciation Period	'1 year
Maximum [Member] | Buildings And Land Improvements [Member]	'
Property, Plant and Equipment [Line Items]	'
Fixed Asset - Depreciation Period	'40 years
Maximum [Member] | Computer Hardware And Software [Member]	'
Property, Plant and Equipment [Line Items]	'
Fixed Asset - Depreciation Period	'7 years
Maximum [Member] | Furniture And Equipment [Member]	'
Property, Plant and Equipment [Line Items]	'
Fixed Asset - Depreciation Period	'10 years
Maximum [Member] | Leasehold Improvements [Member]	'
Property, Plant and Equipment [Line Items]	'
Fixed Asset - Depreciation Period	'20 years

Summary_Of_Significant_Account4

Summary Of Significant Accounting Policies (Schedule Of Amortization Period For Intangible Assets) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'11 years 1 month 6 days	'9 years 1 month 6 days
Purchased Contract Rights [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'7 years 6 months	'7 years 6 months
Provider Contracts [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'13 years 2 months 18 days	'9 years 9 months 18 days
Customer Relationships [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'8 years	'8 years
Trade Names [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'18 years 10 months 18 days	'16 years 3 months 18 days
Minimum [Member] | Purchased Contract Rights [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'5 years	'
Minimum [Member] | Provider Contracts [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'4 years	'
Minimum [Member] | Customer Relationships [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'5 years	'
Minimum [Member] | Trade Names [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'7 years	'
Maximum [Member] | Purchased Contract Rights [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'15 years	'
Maximum [Member] | Provider Contracts [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'15 years	'
Maximum [Member] | Customer Relationships [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'15 years	'
Maximum [Member] | Trade Names [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Amortization Period	'20 years	'

Summary_Of_Significant_Account5

Summary Of Significant Accounting Policies (Schedule Of Allowance For Uncollectible Accounts) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Abstract]	'	'	'
Allowances, beginning of year	$781	$639	$17
Amounts charged to expense	3,138	1,350	865
Write-offs of uncollectible receivables	-2,801	-1,208	-243
Allowances, end of year	$1,118	$781	$639

Summary_Of_Significant_Account6

Summary Of Significant Accounting Policies (Schedule Of Percentage Of Company's Total Revenues) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Georgia [Member]	'	'	'
Percentage of revenues under contracts or subcontracts	'	'	15.00%
Ohio [Member]	'	'	'
Percentage of revenues under contracts or subcontracts	'	'	12.00%
Texas [Member]	'	'	'
Percentage of revenues under contracts or subcontracts	37.00%	40.00%	21.00%

Noncontolling_Interest_and_Acq2

Noncontolling Interest and Acquisitions Non Controlling Interest (Details) (USD $)

3 Months Ended

12 Months Ended

3 Months Ended

3 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Oct. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Louisiana Healthcare Connections [Member]

Louisiana Healthcare Connections [Member]

Louisiana Healthcare Connections [Member]

Louisiana Healthcare Connections [Member]

Centurion [Member]

Centurion [Member]

Centurion [Member]

Casenet, LLC [Member]

Casenet, LLC [Member]

Casenet, LLC [Member]

Home State Health Plan [Member]

Home State Health Plan [Member]

Home State Health Plan [Member]

Noncontrolling Interest [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ownership percentage by parent

'

'

'

'

'

'

'

'

'

'

'

100.00%

100.00%

51.00%

51.00%

51.00%

51.00%

51.00%

100.00%

100.00%

81.00%

95.00%

95.00%

0.00%

Payments to Acquire Additional Interest in Subsidiaries

'

'

'

'

'

'

'

'

$0

$14,429

$0

$10,000

'

'

'

'

'

'

$4,429

'

'

'

'

'

Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income (Loss) from Continuing Operations Attributable to Parent

47,965

50,325

40,289

22,639

18,679

59,438

-16,656

27,072

161,218

88,533

120,518

'

'

'

'

'

'

'

'

'

'

'

'

'

Decrease in equity for purchase of, distribution to and redemption of noncontrolling interest

'

'

'

'

'

'

'

'

0

-12,193

-289

'

'

'

'

'

'

'

'

'

'

'

'

'

Increase in equity for distributions from and consolidation of noncontrolling interest

'

'

'

'

'

'

'

'

8,068

1,092

813

'

'

'

'

'

'

'

'

'

'

'

'

'

Net transfers from (to) noncontrolling interest

'

'

'

'

'

'

'

'

8,068

-11,101

524

'

'

'

'

'

'

'

'

'

'

'

'

'

Changes from net earnings attributable to Centene Corporation and net transfers from (to) the noncontrolling interest

'

'

'

'

'

'

'

'

$169,286

$77,432

$121,042

'

'

'

'

'

'

'

'

'

'

'

'

'

Noncontolling_Interest_and_Acq3

Noncontolling Interest and Acquisitions Acquisitions (Details) (USD $)	3 Months Ended		12 Months Ended				3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Jun. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Apr. 30, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2011
							Casenet, LLC [Member]	Casenet, LLC [Member]	Casenet, LLC [Member]
Business Acquisition [Line Items]	'	'	'	'	'	'	'	'	'
Business Acquisition, Percentage of Voting Interests Acquired	'	'	'	'	'	100.00%	'	'	'
Total consideration	$200,000	'	$142,495	'	'	'	'	'	'
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	'	'	75,425	'	'	'	'	'	'
Business acquisition, cash paid	'	'	67,070	'	'	'	'	'	'
Acquisition of additional ownership	'	'	0	14,429	0	'	4,429	'	'
Goodwill	'	'	348,432	256,288	281,981	'	'	'	'
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	'	'	'	'	'	35,000	'	'	'
Net deferred tax assests	'	'	99,776	71,476	'	'	'	'	'
Ownership percentage by parent	'	'	'	'	'	'	100.00%	100.00%	81.00%
Stock Issued During Period, Shares, New Issues	'	342,640	342,640	'	'	'	'	'	'
Stock Issued During Period, Value, New Issues	'	15,225	15,225	'	'	'	'	'	'
Goodwill, Acquired During Period	'	'	$92,144	'	'	'	'	'	'

Discontinued_Operations_Discon

Discontinued Operations Discontinued Operations (Exit Costs) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'
Restructuring Reserve	$1,271	$2,939	$0
Restructuring and Related Cost, Incurred Cost	1,169	2,939	'
Payments for Restructuring	-2,837	'	'
Employee Severance [Member]	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'
Restructuring Reserve	536	2,939	0
Restructuring and Related Cost, Incurred Cost	434	2,939	'
Payments for Restructuring	-2,837	'	'
Contract Termination [Member]	'	'	'
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'
Restructuring Reserve	735	0	0
Restructuring and Related Cost, Incurred Cost	735	0	'
Payments for Restructuring	$0	'	'

Discontinued_Operations_Discon1

Discontinued Operations Discontinued Operations (Operating Results) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Discontinued Operations and Disposal Groups [Abstract]	'	'	'
Disposal Group, Including Discontinued Operation, Revenue	$248,327	$557,316	$129,105
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	6,165	-134,415	-13,465
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$3,881	($86,674)	($9,300)

Discontinued_Operations_Discon2

Discontinued Operations Discontinued Operations (Assets & Liabilities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'
Statutory capital and surplus	$83,600	'
Assets of Disposal Group, Including Discontinued Operation, Current	77,512	176,996
Disposal Group, Including Discontinued Operations, Long Term Investments and Restricted Deposits	38,305	60,461
Disposal Group, Including Discontinued Operation, Other Noncurrent Assets	0	1,836
Assets of Disposal Group, Including Discontinued Operation	115,817	239,293
Disposal Group, Including Discontinued Operations, Medical Claims Liability	27,637	111,141
Disposal Group, Including Discontinued Operation, Accounts Payable and Accrued Liabilities	2,657	45,975
Disposal Group, Including Discontinued Operation, Other Noncurrent Liabilities	1,028	357
Liabilities of Disposal Group, Including Discontinued Operation	$31,322	$157,473

ShortTerm_And_LongTerm_Investm2

Short-Term And Long-Term Investments And Restricted Deposits (Narrative) (Details)	Dec. 31, 2013
	positions
Investments, Debt and Equity Securities [Abstract]	'
Percentage of investments in securities recorded at fair value that carry a rating by S&P or Moody's of AAA/Aaa	52.00%
Percentage of investments in securities recorded at fair value that carry a rating by S&P or Moody's of AA-/Aa3 or higher	68.00%
Percentage of investments in securities recorded at fair value that carry a rating by S&P or Moody's of A-/A3 or higher	94.00%
Positions from which gross unrealized losses were generated	83
Total number of positions	343

ShortTerm_And_LongTerm_Investm3

Short-Term And Long-Term Investments And Restricted Deposits (Short-Term And Long-Term Investments And Restricted Deposits By Investment Type) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	$945,129	$718,811
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	4,788	8,833
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-8,945	-487
Fair Value	940,972	727,157
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	33,891	0
U.S. Treasury Securities And Obligations Of U.S. Government Corporations And Agencies [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	246,085	110,941
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	245	581
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-7,494	-221
Fair Value	238,836	111,301
Corporate Securities [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	293,912	290,691
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	2,782	4,615
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-608	-195
Fair Value	296,086	295,111
Restricted Certificates Of Deposit [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	5,891	5,890
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Fair Value	5,891	5,890
Restricted Cash Equivalents [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	26,642	14,455
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Fair Value	26,642	14,455
Municipal Securities, General Obligation [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	54,003	85,440
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	555	1,157
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-136	-26
Fair Value	54,422	86,571
Municipal Securities, Pre-Refunded [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	10,835	5,337
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	82	85
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Fair Value	10,917	5,422
Municipal Securities, Revenue [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	68,801	82,781
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	545	1,313
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-292	-30
Fair Value	69,054	84,064
Municipal Securities, Variable Rate Demand Notes [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	28,575	23,385
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Fair Value	28,575	23,385
Asset Backed Securities [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	138,803	73,570
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	579	1,082
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-332	-15
Fair Value	139,050	74,637
Mortgage backed securities	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	33,974	0
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-83	0
Fair Value	33,891	0
Cost And Equity Method Investments [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	22,239	11,298
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Fair Value	22,239	11,298
Life Insurance Contracts [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	15,369	15,023
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Fair Value	$15,369	$15,023

ShortTerm_And_LongTerm_Investm4

Short-Term And Long-Term Investments And Restricted Deposits (Fair Value Of Available-For-Sale Investments With Gross Unrealized Losses By Investment Type And Length Of Time) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses Accumulated In Investments	($7,368)	($485)
Less Than 12 Months, Fair Value	327,939	119,453
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	-1,577	-2
12 Months or More, Fair Value	33,900	201
U.S. Treasury Securities And Obligations Of U.S. Government Corporations And Agencies [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses Accumulated In Investments	-6,188	-219
Less Than 12 Months, Fair Value	172,365	56,033
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	-1,307	-2
12 Months or More, Fair Value	26,454	201
Corporate Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses Accumulated In Investments	-400	-195
Less Than 12 Months, Fair Value	52,725	44,208
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	-207	0
12 Months or More, Fair Value	5,020	0
Municipal Securities, General Obligation [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses Accumulated In Investments	-72	-26
Less Than 12 Months, Fair Value	3,480	7,930
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	-63	0
12 Months or More, Fair Value	2,426	0
Municipal Securities, Revenue [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses Accumulated In Investments	-292	-30
Less Than 12 Months, Fair Value	27,789	3,090
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	0	0
12 Months or More, Fair Value	0	0
Asset Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses Accumulated In Investments	-333	-15
Less Than 12 Months, Fair Value	37,689	8,192
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	0	0
12 Months or More, Fair Value	0	0
Mortgage backed securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses Accumulated In Investments	-83	0
Less Than 12 Months, Fair Value	33,891	0
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	0	0
12 Months or More, Fair Value	$0	$0

ShortTerm_And_LongTerm_Investm5

Short-Term And Long-Term Investments And Restricted Deposits (Contractual Maturities Of Short-Term And Long-Term Investments And Restricted Deposits) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
One year or less, Amortized Cost	$101,537	$136,997
One year through five years, Amortized Cost	609,755	429,053
Five years through ten years, Amortized Cost	157,003	93,907
Greater than ten years, Amortized Cost	29,900	24,599
Total, Amortized Cost	898,195	684,556
One year or less, Fair Value	102,126	138,101
One year through five years, Fair Value	610,589	435,728
Five years through ten years, Fair Value	151,221	93,778
Greater than ten years, Fair Value	30,090	25,264
Total, Fair Value	894,026	692,871
Restricted Deposits [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
One year or less, Amortized Cost	40,633	33,897
One year through five years, Amortized Cost	6,301	358
Five years through ten years, Amortized Cost	0	0
Greater than ten years, Amortized Cost	0	0
Total, Amortized Cost	46,934	34,255
One year or less, Fair Value	40,637	33,928
One year through five years, Fair Value	6,309	358
Five years through ten years, Fair Value	0	0
Greater than ten years, Fair Value	0	0
Total, Fair Value	$46,946	$34,286

Fair_Value_Measurements_Fair_V

Fair Value Measurements (Fair Value Measurements By Level For Assets Measured At Fair Value On A Recurring Basis) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Cash and cash equivalents	$974,304	$745,933
U.S. Treasury securities and obligations of U.S. government corporations and agencies	224,423	97,360
Corporate securities	296,086	295,111
Municipal securities, General obligation	54,422	86,571
Municipal securities, Pre-refunded	10,917	5,422
Municipal securities, Revenue	69,054	84,064
Municipal securities, Variable rate demand notes	28,575	23,385
Asset backed securities	139,050	74,637
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	33,891	0
Total investments	856,418	666,550
Cash and cash equivalents	26,642	14,455
Certificates of deposit	5,891	5,890
U.S. Treasury securities and obligations of U.S. government corporations and agencies	14,413	13,941
Total restricted deposits	46,946	34,286
Interest rate swap contract	9,576	16,304
Total assets at fair value	1,887,244	1,463,073
Level I [Member]	'	'
Cash and cash equivalents	974,304	745,933
U.S. Treasury securities and obligations of U.S. government corporations and agencies	212,185	57,114
Corporate securities	0	0
Municipal securities, General obligation	0	0
Municipal securities, Pre-refunded	0	0
Municipal securities, Revenue	0	0
Municipal securities, Variable rate demand notes	0	0
Asset backed securities	0	0
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	0	0
Total investments	212,185	57,114
Cash and cash equivalents	26,642	14,455
Certificates of deposit	5,891	5,890
U.S. Treasury securities and obligations of U.S. government corporations and agencies	14,413	13,941
Total restricted deposits	46,946	34,286
Interest rate swap contract	0	0
Total assets at fair value	1,233,435	837,333
Level II [Member]	'	'
Cash and cash equivalents	0	0
U.S. Treasury securities and obligations of U.S. government corporations and agencies	12,238	40,246
Corporate securities	296,086	295,111
Municipal securities, General obligation	54,422	86,571
Municipal securities, Pre-refunded	10,917	5,422
Municipal securities, Revenue	69,054	84,064
Municipal securities, Variable rate demand notes	28,575	23,385
Asset backed securities	139,050	74,637
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	33,891	0
Total investments	644,233	609,436
Cash and cash equivalents	0	0
Certificates of deposit	0	0
U.S. Treasury securities and obligations of U.S. government corporations and agencies	0	0
Total restricted deposits	0	0
Interest rate swap contract	9,576	16,304
Total assets at fair value	653,809	625,740
Level III [Member]	'	'
Cash and cash equivalents	0	0
U.S. Treasury securities and obligations of U.S. government corporations and agencies	0	0
Corporate securities	0	0
Municipal securities, General obligation	0	0
Municipal securities, Pre-refunded	0	0
Municipal securities, Revenue	0	0
Municipal securities, Variable rate demand notes	0	0
Asset backed securities	0	0
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	0	0
Total investments	0	0
Cash and cash equivalents	0	0
Certificates of deposit	0	0
U.S. Treasury securities and obligations of U.S. government corporations and agencies	0	0
Total restricted deposits	0	0
Interest rate swap contract	0	0
Total assets at fair value	$0	$0

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value Disclosures [Abstract]	'	'
Transfers from Level I to Level II	$1,143	'
Transfers from Level II to Level I	26,301	'
Life insurance contracts and cost-method investments	$37,608	$26,321

Notes_Receivable_Narrative_Det

Notes Receivable (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Notes Receivable [Line Items]	'	'	'	'
Convertible Notes Receivable, Net	'	'	'	$30,000
Consideration Committed for Sale of Convertible Notes	50,000	'	'	'
Imputed Interest on Note Receivable, Discount	2,120	'	'	'
Gain on Sale of Convertible Notes	17,880	0	17,880	0
Note Receivable Due December 2012 [Member]	'	'	'	'
Notes Receivable [Line Items]	'	'	'	'
Notes Receivable, Current	30,000	'	'	'
Note Receivable Due September 2013 [Member]	'	'	'	'
Notes Receivable [Line Items]	'	'	'	'
Notes Receivable, Current	10,000	9,483	'	'
Note Receivable Due September 2014 [Member]	'	'	'	'
Notes Receivable [Line Items]	'	'	'	'
Notes Receivable, Noncurrent	$10,000	'	'	'

Property_Software_And_Equipmen2

Property, Software And Equipment (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]	'	'	'
Property, software and equipment, gross	$639,829	$578,550	'
Less accumulated depreciation	-244,422	-202,657	'
Property, software and equipment, net	395,407	375,893	'
Depreciation expense	52,234	48,942	42,098
Computer Software [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, software and equipment, gross	184,983	164,755	'
Buildings [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, software and equipment, gross	206,058	193,186	'
Land [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, software and equipment, gross	69,705	70,276	'
Computer Hardware [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, software and equipment, gross	69,087	57,389	'
Furniture And Office Equipment [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, software and equipment, gross	53,180	43,136	'
Leasehold Improvements [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, software and equipment, gross	56,816	49,808	'
Assets Held Under Capital Leases [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Less accumulated depreciation	-1,782	-1,595	'
Property, software and equipment, net	$5,815	$6,133	'

Goodwill_And_Intangible_Assets2

Goodwill And Intangible Assets (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]	'	'
Facts and circumstances leading to impairment	'During the second quarter of 2012, the Company's subsidiary, Celtic Insurance Company, experienced a high level of medical costs for individual health policies, especially for recently issued policies related to members converted from another insurer during the first quarter of 2012. Additionally, in June 2012, the U.S. Supreme Court upheld the constitutionality of the Patient Protection and Affordable Care Act which limits the profitability of the individual health insurance business because of minimum medical loss ratios, guaranteed issue policies, and increased competition in the exchange market.	'
Goodwill and intangible asset impairment	$28,033	'
Impaired intangible asset, income statement classification	'recorded as an impairment loss in the consolidated statement of operations	'
Impairment of intangible assets (excluding goodwill)	2,340	'
Goodwill, impairment loss	25,693	-25,693
Nondeductible impairment loss	$26,589	'

Goodwill_And_Intangible_Assets3

Goodwill And Intangible Assets (Schedule Of Changes In Goodwill By Operating Segment) (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill [Line Items]	'	'	'	'
Goodwill	'	$348,432	$256,288	$281,981
Goodwill, Acquired During Period	'	92,144	'	'
Goodwill, impairment loss	25,693	'	-25,693	'
Medicaid Managed Care [Member]	'	'	'	'
Goodwill [Line Items]	'	'	'	'
Goodwill	'	151,402	151,402	151,402
Goodwill, Acquired During Period	'	0	0	'
Specialty Services [Member]	'	'	'	'
Goodwill [Line Items]	'	'	'	'
Goodwill	'	197,030	104,886	130,579
Goodwill, Acquired During Period	'	92,144	'	'
Goodwill, impairment loss	'	'	($25,693)	'

Goodwill_And_Intangible_Assets4

Goodwill And Intangible Assets (Schedule Of Intangible Assets) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]	'	'	'
Amortization expenses	$6,489	$4,822	$5,561
Intangible assets	79,616	44,616	'
Weighted Average Life in Years	'11 years 1 month 6 days	'9 years 1 month 6 days	'
Total accumulated amortization	-30,836	-24,348	'
Intangible Assets, Net, Total	48,780	20,268	'
Purchased Contract Rights [Member]	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'
Intangible assets	21,988	21,988	'
Weighted Average Life in Years	'7 years 6 months	'7 years 6 months	'
Total accumulated amortization	-13,459	-11,010	'
Provider Contracts [Member]	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'
Intangible assets	35,537	2,737	'
Weighted Average Life in Years	'13 years 2 months 18 days	'9 years 9 months 18 days	'
Total accumulated amortization	-3,767	-1,241	'
Customer Relationships [Member]	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'
Intangible assets	13,396	13,396	'
Weighted Average Life in Years	'8 years	'8 years	'
Total accumulated amortization	-11,425	-10,214	'
Trade Names [Member]	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'
Intangible assets	8,695	6,495	'
Weighted Average Life in Years	'18 years 10 months 18 days	'16 years 3 months 18 days	'
Total accumulated amortization	($2,185)	($1,883)	'

Goodwill_And_Intangible_Assets5

Goodwill And Intangible Assets (Schedule Of Future Amortization Expenses) (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]	'
2014	$6,800
2015	5,900
2016	5,900
2017	4,400
2018	$2,600

Medical_Claims_Liability_Sched

Medical Claims Liability (Schedule Of Change In Medical Claims Liability) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]	'	'	'
Balance, January 1,	$815,161	$518,840	$456,765
Incurred related to: Current year	9,072,867	6,836,177	4,256,645
Incurred related to: Prior years	-78,226	-55,096	-65,377
Total incurred	8,994,641	6,781,081	4,191,268
Paid related to: Current year	7,975,367	6,024,720	3,744,475
Paid related to: Prior years	722,726	460,040	384,718
Total paid	8,698,093	6,484,760	4,129,193
Balance, December 31,	1,111,709	815,161	518,840
Reinsurance recoverables	$10,427	$9,094	'

Debt_Narrative_Details

Debt (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended		1 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	31-May-11	Nov. 30, 2012	Dec. 31, 2013	Dec. 31, 2012
				5.75% Senior Notes [Member]	5.75% Senior Notes [Member]	Non-recourse Mortgage Note Due January 1, 2021 [Member]	Mortgage Note Due August 31, 2014 [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'
Line of Credit Facility, Covenant Terms	'The agreement contains non-financial and financial covenants, including requirements of minimum fixed charge coverage ratios, maximum debt-to-EBITDA ratios and minimum tangible net worth. The Company is required not to exceed a maximum debt-to-EBITDA ratio of 3.0 to 1.0.	'	'	'	'	'	'
Line of Credit Facility, Current Borrowing Capacity	$500,000	$500,000	'	'	'	'	'
Senior notes, at par	425,000	425,000	425,000	250,000	175,000	'	'
Interest rate on notes, percentage	'	'	'	5.75%	5.75%	'	'
Debt maturity date	'	'	'	1-Jun-17	'	1-Jan-21	'
Senior notes, effective yield	'	'	'	6.00%	4.29%	'	'
Debt Instrument, Unamortized Premium	6,052	6,052	7,823	'	'	'	'
Fair value of swap agreements	9,576	9,576	16,304	'	'	'	'
Variable rate of swap, percentage	3.74%	3.74%	'	'	'	'	'
Revolving credit facility, maximum borrowing capacity	500,000	500,000	'	'	'	'	'
Revolving credit facility, due date	'	1-Jun-18	'	'	'	'	'
Line of Credit Facility, Amount Outstanding	150,000	150,000	'	'	'	'	'
Letters of credit outstanding amount	28,757	28,757	'	'	'	'	'
Letters of credit bore interest	0.51%	0.51%	'	'	'	'	'
Notes Payable	'	'	'	'	'	72,785	8,700
Mortgage note non-recourse interest rate	'	'	'	'	'	5.14%	'
Net Book Value Of Collateralized Properties	'	'	'	'	'	160,246	'
Weighted average interest rate of outstanding borrowings	3.31%	3.31%	'	'	'	'	'
Fair value of outstanding debt	672,529	672,529	543,611	'	'	'	'
Surety Bonds	$102,568	$102,568	'	'	'	'	'

Debt_Schedule_Of_Debt_Details

Debt (Schedule Of Debt) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
Senior notes, at par	$425,000	$425,000
Debt Instrument, Unamortized Premium	6,052	7,823
Interest rate swap fair value	9,576	16,304
Senior notes, net	440,628	449,127
Revolving credit agreement	150,000	0
Mortgage notes payable	72,785	84,081
Capital leases and other	5,349	5,646
Total debt	668,762	538,854
Less current portion	-3,065	-3,373
Long-term debt	$665,697	$535,481

Debt_Schedule_Of_Aggregate_Mat

Debt (Schedule Of Aggregate Maturities Of Debt) (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt [Abstract]	'
2014	$3,065
2015	3,188
2016	3,353
2017	428,525
2018	153,702
Thereafter	61,301
Total	$653,134

Interest_Rate_Swap_Details

Interest Rate Swap (Details) (USD $)	1 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	31-May-11	Dec. 31, 2013	Dec. 31, 2012
Interest Rate Swap [Abstract]	'	'	'
Notional amount of interest rate swap agreements	$250,000	'	'
Interest rate swap agreements expire date	'	'June 1, 2017	'
Interest rate received in swap agreements	5.75%	'	'
Interest rate paid on swap agreements	'three month LIBOR plus 3.5%	'	'
Variable interest rate	'	3.74%	'
Fair value of swap agreements	'	$9,576	$16,304

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Oct. 26, 2009
Stockholders' Equity Note [Abstract]	'	'	'	'	'
Preferred stock, shares authorized (in shares)	'	10,000,000	'	'	'
Preferred Stock, par value (in dollars per share)	'	$0.00	'	'	'
Common stock, shares authorized to repurchase (in shares)	'	'	'	'	4,000,000
Remaining number of shares available to be repurchased	'	1,667,724	'	'	'
Common stock repurchases (in shares)	'	344,064	287,804	'	'
Payments for repurchase of common stock	'	$19,779	$12,741	$7,809	'
Stock Issued During Period, Shares, Acquisitions	1,716,690	'	'	'	'
Stock Issued During Period, Shares, New Issues	342,640	342,640	'	'	'
Stock Issued During Period, Value, New Issues	$15,225	$15,225	'	'	'

Statutory_Capital_Requirements1

Statutory Capital Requirements And Dividend Restrictions (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Statutory Capital Requirements And Dividend Restrictions [Abstract]	'	'
Statutory capital and surplus	$1,279,700	$990,300
Required minimum aggregate statutory capital and surplus	$686,400	$617,000

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]	'	'	'
Federal and state net operating losses acquired in business combinations	$6,547	'	'
Valuation allowance additions in the tax provision	1,301	2,093	'
Valuation allowance reductions	1,362	2,289	'
Potential benefits included in reserve that would impact effective tax rate	3,274	4,095	'
Liabilities included in the reserve	'	3,775	'
Tax benefit recognized due to decrease in accrued interest	310	170	'
Interest accrued, net of federal benefit	$623	$933	$1,157
Minimum [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Federal Net Operating Losses Expire Period	'2020	'	'
State Net Operating Losses Expire Period	'2014	'	'
Maximum [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Federal Net Operating Losses Expire Period	'2032	'	'
State Net Operating Losses Expire Period	'2034	'	'

Income_Taxes_Consolidated_Inco

Income Taxes (Consolidated Income Tax Expense) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Federal	$120,858	$47,528	$63,388
State and local	5,857	-4,368	5,157
Total current provision	126,715	43,160	68,545
Deferred provision	-19,635	4,252	2,142
Total provision for income taxes	$107,080	$47,412	$70,687

Income_Taxes_Reconciliation_Of

Income Taxes (Reconciliation Of The Tax Provision At The U.S. Federal Statutory Rate To The Provision For Income Taxes) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Earnings from continuing operations, before income tax expense	$268,917	$122,791	$188,350
Less flow through noncontrolling interest	960	-2,539	-2,855
Earnings from continuing operations, less noncontrolling interest, before income tax expense	267,957	125,330	191,205
Tax provision at the U.S. federal statutory rate	93,785	43,866	66,922
State income taxes, net of federal income tax benefit	2,871	-2,288	3,381
Nondeductible goodwill impairment	0	8,487	0
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount	12,519	1,108	2,705
Other, net	-2,095	-3,761	-2,321
Total provision for income taxes	$107,080	$47,412	$70,687

Income_Taxes_Tax_Effects_Of_Te

Income Taxes (Tax Effects Of Temporary Differences Which Give Rise To Deferred Tax Assets And Liabilities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Medical claims liability and other accruals	$53,943	$37,413
State net operating loss carry forward	9,530	9,055
Stock compensation	14,223	12,615
Other	30,199	20,573
Deferred tax assets	107,895	79,656
Valuation allowance	-8,119	-8,180
Net deferred tax assests	99,776	71,476
Intangible assets	18,278	12,441
Prepaid assets and other	5,621	4,767
Depreciation and amortization	30,411	31,741
Other	1,615	5,624
Deferred Tax Liabilities	55,925	54,573
Net deferred tax assets	$43,851	$16,903

Income_Taxes_Reserve_For_Uncer

Income Taxes (Reserve For Uncertain Tax Positions) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]	'	'
Balance as of January 1	$7,870	$13,552
Increase based on tax positions during the current year	338	4,107
Increase based on tax positions during the prior year	164	451
Decreases based on tax positions taken in a prior period	0	-9,925
Settlements	-4,390	-53
Statute of limitation lapses	-708	-262
Balance as of December 31	$3,274	$7,870

Stock_Incentive_Plans_Narrativ

Stock Incentive Plans (Narrative) (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Length of time options exercisable, years	'10 years	'	'
Shares available for future awards	1,414,240	'	'
Allocated Share-based Compensation Expense	$36,153	$25,001	$18,141
Income tax benefit recognized	7,575	8,952	5,804
Fair value of restricted stock and restricted stock units	49,032	38,576	22,280
Unrecognized compensation cost related to non-vested share	87,901	'	'
Weighted-average period	'1 year 8 months 12 days	'	'
Actual tax benefit realized	$508	$1,078	$955
Employee stock purchase plan issued	42,084	47,613	34,966
Stock Options [Member] | Minimum [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock options vesting period, years	'3 years	'	'
Stock Options [Member] | Maximum [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock options vesting period, years	'5 years	'	'
Restricted Stock Units Awards [Member] | Minimum [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock options vesting period, years	'1 year	'	'
Restricted Stock Units Awards [Member] | Maximum [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock options vesting period, years	'10 years	'	'

Stock_Incentive_Plans_Summary_

Stock Incentive Plans (Summary Of Stock Option Activity) (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013
Stock Incentive Plans [Abstract]	'
Outstanding as of December 31, 2012	1,299,396
Shares granted	10,000
Shares exercised	-361,538
Shares forfeited	-663
Outstanding as of December 31, 2013	947,195
Exercisable as of December 31, 2013	921,462
Weighted Average Exercise Price Outstanding as of December 31, 2012	$22.39
Weighted Average Exercise Price Granted	$44.58
Weighted Average Exercise Price Exercised	$20.32
Weighted Average Exercise Price Forfeited	$17.86
Weighted Average Exercise Price Outstanding as of December 31, 2013	$23.41
Weighted Average Exercise Price Exercisable as of December 31, 2013	$23.21
Aggregate Intrinsic Value Outstanding as of December 31, 2013	$33,659
Aggreggate Intrinsic Value Exercisable as of December 31, 2013	$32,937
Weighted Average Remaining Contractual Term Outstanding as of December 31, 2013	'2 years 9 months 10 days
Weighted Average Remaining Contractual Term Exercisable as of December 31, 2013	'2 years 7 months 29 days

Stock_Incentive_Plans_Option_P

Stock Incentive Plans (Option Pricing Assumptions) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Stock Incentive Plans [Abstract]	'	'		'
Expected life (in years)	'5 years 1 month 20 days	'		'5 years 2 months 12 days
Risk-free interest rate	0.80%	0.00%	[1]	0.90%
Expected volatility	48.10%	0.00%	[1]	49.90%
Expected dividend yield	0.00%	0.00%	[1]	0.00%
[1]	No options were awarded in the year ended December 31, 2012.

Stock_Incentive_Plans_Schedule

Stock Incentive Plans (Schedule Of Other Information Pertaining To Option Activity) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Stock Incentive Plans [Abstract]	'	'		'
Weighted-average fair value of options granted	$19.04	$0	[1]	$13.94
Total intrinsic value of stock options exercised	$12,845	$24,120	[1]	$11,744
[1]	No options were awarded in the year ended December 31, 2012.

Stock_Incentive_Plans_NonVeste

Stock Incentive Plans (Non-Vested Restricted Stock And Restricted Stock) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Stock Incentive Plans [Abstract]	'
Non-vested balance as of December 31, 2012	2,058,908
Shares Granted	1,037,542
Shares Vested	-961,741
Shares Forfeited	-45,116
Non-vested balance as of December 31, 2013	2,089,593
Weighted Average Grant Date Fair Value, Non-vested balance as of December 31, 2012	$37.25
Weighted Average Grant Date Fair Value, Granted	$55.36
Weighted Average Grant Date Fair Value, Vested	$33.57
Weighted Average Grant Date Fair Value, Forfeited	$38.91
Weighted Average Grant Date Fair Value, Non-vested balance as of December 31, 2013	$47.90

Retirement_Plan_Details

Retirement Plan (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Retirement Plan [Abstract]	'	'	'
Defined Contribution Plan, Cost Recognized	$9,422	$6,771	$5,119

Commitments_Details

Commitments (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments [Abstract]	'	'	'
Rent expense	$30,562	$27,564	$22,537
2014	25,350	'	'
2015	25,871	'	'
2016	24,202	'	'
2017	19,336	'	'
2018	12,628	'	'
Thereafter	18,800	'	'
Annual non-cancelable minimum lease payments, Total	$126,187	'	'

Contingencies_Contingencies_De

Contingencies Contingencies (Details)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Loss Contingency, Allegations	'In October 2012, the Company notified the Kentucky Cabinet for Health and Family Services (Cabinet) that it was exercising a contractual right that it believes allows the Company to terminate its Medicaid managed care contract with the Commonwealth of Kentucky (Commonwealth) effective July 5, 2013.  The Company also filed a lawsuit in Franklin Circuit Court against the Commonwealth seeking a declaration of the Company's right to terminate the contract on July 5, 2013.  In April 2013, the Commonwealth answered that lawsuit and filed counterclaims against the Company seeking declaratory relief and damages.  In May 2013, the Franklin Circuit Court ruled that Kentucky Spirit does not have a contractual right to terminate the contract early.  Kentucky Spirit has appealed that ruling to the Kentucky Court of Appeals. The Company also filed a formal dispute with the Cabinet for damages incurred under the contract, which was later appealed to and denied by the Finance and Administration Cabinet.  In response, the Company filed a lawsuit in April 2013, in Franklin Circuit Court seeking damages against the Commonwealth for losses sustained due to the Commonwealth's alleged breaches. This lawsuit was subsequently consolidated with the original lawsuit for declaratory relief and continues to proceed. Kentucky Spirit's efforts to resolve issues with the Commonwealth were unsuccessful and on July 5, 2013, Kentucky Spirit proceeded with its previously announced exit.  By letter dated July 11, 2013, the Commonwealth alleged that Kentucky Spirit's exit constitutes a material breach of contract.  The letter states that, unless Kentucky Spirit cures the alleged material breach within thirty days, the Commonwealth will seek to recover substantial damages and to enforce its rights under Kentucky Spirit's $25,000 performance bond.  Any claim for damages by the Commonwealth may include the costs of transition and the additional costs to the Commonwealth to cover Kentucky Spirit's former members through July 5, 2014. Kentucky Spirit is pursuing its litigation claims for damages against the Commonwealth and will vigorously defend against any allegations that it has breached the contract.
Loss Contingency, Inestimable Loss	'The resolution of the Kentucky litigation matters may result in a range of possible outcomes.  If the Company prevails on its claims, Kentucky Spirit would be entitled to damages under its lawsuit.  If the Commonwealth prevails, a liability to the Commonwealth could be recorded.  The Company is unable to estimate the ultimate outcome resulting from the Kentucky litigation.  As a result, the Company has not recorded any receivable or any liability for potential damages under the contract as of December 31, 2013.  While uncertain, the ultimate resolution of the pending litigation could have a material effect on the financial position, cash flow or results of operations of the Company in the period it is resolved or becomes known.

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Earnings from continuing operations, net of income tax expense	$47,965	$50,325	$40,289	$22,639	$18,679	$59,438	($16,656)	$27,072	$161,218	$88,533	$120,518
Discontinued operations, net of tax	5,275	-952	-805	363	-9,618	-55,619	-18,343	-3,094	3,881	-86,674	-9,300
Net earnings attributable to Centene Corporation	$53,240	$49,373	$39,484	$23,002	$9,061	$3,819	($34,999)	$23,978	$165,099	$1,859	$111,218
Weighted average number of common shares outstanding (in shares)	'	'	'	'	'	'	'	'	54,126,545	51,509,366	50,198,954
Common stock equivalents (as determined by applying the treasury stock method)	'	'	'	'	'	'	'	'	2,120,628	2,205,009	2,275,284
Weighted average number of common shares and potential dilutive common shares outstanding (in shares)	'	'	'	'	'	'	'	'	56,247,173	53,714,375	52,474,238
Continuing operations, Basic	$0.87	$0.92	$0.74	$0.43	$0.36	$1.15	($0.32)	$0.53	$2.98	$1.72	$2.40
Discontinued operations, Basic	$0.10	($0.02)	($0.02)	$0.01	($0.19)	($1.08)	($0.36)	($0.06)	$0.07	($1.68)	($0.18)
Earnings per common share, Basic	$0.97	$0.90	$0.72	$0.44	$0.17	$0.07	($0.68)	$0.47	$3.05	$0.04	$2.22
Continuing operations, Diluted	$0.84	$0.88	$0.71	$0.41	$0.35	$1.10	($0.32)	$0.51	$2.87	$1.65	$2.30
Discontinued operations, Diluted	$0.09	($0.01)	$0.01	$0.01	($0.18)	($1.03)	($0.36)	($0.06)	$0.07	($1.62)	($0.18)
Earnings per common share, Diluted	$0.93	$0.87	$0.72	$0.42	$0.17	$0.07	($0.68)	$0.45	$2.94	$0.03	$2.12
Anti-dilutive stock options, restricted stock and restricted stock units excluded from the calculation of diluted earnings per common share	'	'	'	'	'	'	'	'	93,539	142,425	106,219

Segment_Information_Details

Segment Information (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
									segments
Number of reportable segments	'	'	'	'	'	'	'	'	2	'	'
Premium and service revenues from external or internal customers	$2,931,740	$2,795,569	$2,610,538	$2,525,482	$2,272,050	$2,308,075	$1,967,362	$1,562,809	$10,863,329	$8,110,296	$5,211,477
Premium and service revenues	'	'	'	'	'	'	'	'	10,526,040	7,681,631	5,051,902
Earnings (loss) from operations	'	'	'	'	'	'	'	'	277,417	107,966	203,803
Total assets	3,529,300	'	'	'	2,773,905	'	'	'	3,529,300	2,773,905	'
External Customer [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues from external or internal customers	'	'	'	'	'	'	'	'	10,526,040	7,681,631	5,051,902
Internal Customer [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues from external or internal customers	'	'	'	'	'	'	'	'	0	0	0
Operating Segments [Member] | Medicaid Managed Care [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues	'	'	'	'	'	'	'	'	9,781,814	7,212,039	4,636,239
Earnings (loss) from operations	'	'	'	'	'	'	'	'	197,844	62,867	161,890
Total assets	2,817,519	'	'	'	2,163,347	'	'	'	2,817,519	2,163,347	1,709,271
Operating Segments [Member] | Specialty Services [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues	'	'	'	'	'	'	'	'	2,932,520	2,107,007	1,190,474
Earnings (loss) from operations	'	'	'	'	'	'	'	'	79,573	45,099	41,913
Total assets	595,964	'	'	'	371,265	'	'	'	595,964	371,265	383,259
Operating Segments [Member] | External Customer [Member] | Medicaid Managed Care [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues from external or internal customers	'	'	'	'	'	'	'	'	9,740,720	7,124,720	4,571,430
Operating Segments [Member] | External Customer [Member] | Specialty Services [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues from external or internal customers	'	'	'	'	'	'	'	'	785,320	556,911	480,472
Operating Segments [Member] | Internal Customer [Member] | Medicaid Managed Care [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues from external or internal customers	'	'	'	'	'	'	'	'	41,094	87,319	64,809
Operating Segments [Member] | Internal Customer [Member] | Specialty Services [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues from external or internal customers	'	'	'	'	'	'	'	'	2,147,200	1,550,096	710,002
Intersegment Eliminations [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues	'	'	'	'	'	'	'	'	-2,188,294	-1,637,415	-774,811
Earnings (loss) from operations	'	'	'	'	'	'	'	'	0	0	0
Total assets	0	'	'	'	'	'	'	0	0	'	0
Intersegment Eliminations [Member] | External Customer [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues from external or internal customers	'	'	'	'	'	'	'	'	0	0	0
Intersegment Eliminations [Member] | Internal Customer [Member]	'	'	'	'	'	'	'	'	'	'	'
Premium and service revenues from external or internal customers	'	'	'	'	'	'	'	'	-2,188,294	-1,637,415	-774,811
Continuing Operations [Member]	'	'	'	'	'	'	'	'	'	'	'
Total assets	$3,413,483	'	'	'	$2,534,612	'	'	'	$3,413,483	$2,534,612	$2,092,530

Quarterly_Selected_Financial_I2

Quarterly Selected Financial Information (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Selected Financial Information [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Total revenues	$2,931,740	$2,795,569	$2,610,538	$2,525,482	$2,272,050	$2,308,075	$1,967,362	$1,562,809	$10,863,329	$8,110,296	$5,211,477
Discontinued operations, net of income tax expense (benefit)	5,275	-952	-805	363	-9,618	-55,619	-18,343	-3,094	3,881	-86,674	-9,300
Net Income (Loss) Attributable to Parent	53,240	49,373	39,484	23,002	9,061	3,819	-34,999	23,978	165,099	1,859	111,218
Continuing operations	$0.87	$0.92	$0.74	$0.43	$0.36	$1.15	($0.32)	$0.53	$2.98	$1.72	$2.40
Discontinued operations	$0.10	($0.02)	($0.02)	$0.01	($0.19)	($1.08)	($0.36)	($0.06)	$0.07	($1.68)	($0.18)
Income (Loss) from Continuing Operations Attributable to Parent	$47,965	$50,325	$40,289	$22,639	$18,679	$59,438	($16,656)	$27,072	$161,218	$88,533	$120,518
Earnings per common share, Basic	$0.97	$0.90	$0.72	$0.44	$0.17	$0.07	($0.68)	$0.47	$3.05	$0.04	$2.22
General and Administrative Expense Ratio	8.90%	9.10%	8.90%	8.40%	8.40%	8.40%	8.50%	10.40%	'	'	'
Continuing operations	$0.84	$0.88	$0.71	$0.41	$0.35	$1.10	($0.32)	$0.51	$2.87	$1.65	$2.30
Discontinued operations	$0.09	($0.01)	$0.01	$0.01	($0.18)	($1.03)	($0.36)	($0.06)	$0.07	($1.62)	($0.18)
Earnings per common share, Diluted	$0.93	$0.87	$0.72	$0.42	$0.17	$0.07	($0.68)	$0.45	$2.94	$0.03	$2.12
Period End At Risk Membership	2,723,200	2,612,500	2,563,400	2,553,400	2,424,500	2,357,600	2,254,000	2,003,800	'	'	'
Health Benefit Ratio	88.10%	87.80%	88.40%	90.20%	90.70%	88.70%	91.20%	87.10%	'	'	'

Condensed_Financial_Informatio2

Condensed Financial Information Of Registrant (Condensed Balance Sheets) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified
Cash and cash equivalents	$1,038,073	$843,952	$573,698	$434,166
Short-term investments	102,126	138,101	'	'
Other current assets	217,661	93,322	'	'
Total current assets	1,800,173	1,405,825	'	'
Long-term investments	791,900	554,770	'	'
Other long-term assets	59,357	64,278	'	'
Total assets	3,529,300	2,773,905	'	'
Current liabilities	1,559,121	1,229,313	'	'
Long-term debt	665,697	535,481	'	'
Other long-term liabilities	60,015	54,987	'	'
Total liabilities	2,285,861	1,820,138	'	'
Common stock, $.001 par value; authorized 100,000,000 shares; 58,673,215 issued and 55,319,239 outstanding at December 31, 2013, and 55,339,160 issued and 52,329,248 outstanding at December 31, 2012	59	55	'	'
Additional paid-in capital	594,326	450,856	'	'
Unrealized gain on investments, net of tax	-2,620	5,189	'	'
Retained earnings	731,919	566,820	'	'
Treasury stock, at cost (3,353,976 and 3,009,912 shares, respectively)	-89,643	-69,864	'	'
Total Centene stockholders' equity	1,234,041	953,056	'	'
Noncontrolling interest	9,398	711	'	'
Total stockholders' equity	1,243,439	953,767	936,419	797,055
Total liabilities and stockholders' equity	3,529,300	2,773,905	'	'
Parent Company [Member]	'	'	'	'
Cash and cash equivalents	2,740	22,279	28,527	9,380
Short-term investments	6,000	6,500	'	'
Other current assets	124,903	42,230	'	'
Total current assets	133,643	71,009	'	'
Long-term investments	8,070	1,356	'	'
Investment in subsidiaries	1,667,258	1,298,648	'	'
Other long-term assets	31,876	42,523	'	'
Total assets	1,840,847	1,413,536	'	'
Current liabilities	4,460	4,333	'	'
Long-term debt	590,628	449,127	'	'
Other long-term liabilities	2,320	6,309	'	'
Total liabilities	597,408	459,769	'	'
Common stock, $.001 par value; authorized 100,000,000 shares; 58,673,215 issued and 55,319,239 outstanding at December 31, 2013, and 55,339,160 issued and 52,329,248 outstanding at December 31, 2012	59	55	'	'
Additional paid-in capital	594,326	450,856	'	'
Unrealized gain on investments, net of tax	-2,620	5,189	'	'
Retained earnings	731,919	566,820	'	'
Treasury stock, at cost (3,353,976 and 3,009,912 shares, respectively)	-89,643	-69,864	'	'
Total Centene stockholders' equity	1,234,041	953,056	'	'
Noncontrolling interest	9,398	711	'	'
Total stockholders' equity	1,243,439	953,767	'	'
Total liabilities and stockholders' equity	$1,840,847	$1,413,536	'	'

Condensed_Financial_Informatio3

Condensed Financial Information Of Registrant Condensed Balance Sheets (Parenthetical) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common Stock, Shares, Issued	58,673,215	55,339,160
Common Stock, Shares, Outstanding	55,319,239	52,329,248
Treasury Stock, Shares	3,353,976	3,009,912
Parent Company [Member]	'	'
Short-term investments, Amortized cost	$6,500	$0
Long-term investments, Amortized cost	$1,356	$4,164
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common Stock, Shares, Issued	55,339,160	53,586,726
Common Stock, Shares, Outstanding	52,329,248	50,864,618
Treasury Stock, Shares	3,009,912	2,722,108

Condensed_Financial_Informatio4

Condensed Financial Information Of Registrant (Condensed Statements Of Operations) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
General and administrative expenses	'	'	'	'	'	'	'	'	$931,137	$677,157	$577,898
Investment and other income	'	'	'	'	'	'	'	'	18,457	35,285	13,355
Interest Expense	'	'	'	'	'	'	'	'	-26,957	-20,460	-20,320
Earnings (loss) before income taxes	'	'	'	'	'	'	'	'	268,917	122,791	188,350
Income tax expense	'	'	'	'	'	'	'	'	107,080	47,412	70,687
Net earnings (loss) before equity in subsidiaries	'	'	'	'	'	'	'	'	165,718	-11,295	108,363
Net earnings attributable to Centene Corporation	53,240	49,373	39,484	23,002	9,061	3,819	-34,999	23,978	165,099	1,859	111,218
Basic earnings (loss) per common share (in dollars per share)	$0.97	$0.90	$0.72	$0.44	$0.17	$0.07	($0.68)	$0.47	$3.05	$0.04	$2.22
Diluted earnings (loss) per common share (in dollars per share)	$0.93	$0.87	$0.72	$0.42	$0.17	$0.07	($0.68)	$0.45	$2.94	$0.03	$2.12
Basic	'	'	'	'	'	'	'	'	54,126,545	51,509,366	50,198,954
Diluted	'	'	'	'	'	'	'	'	56,247,173	53,714,375	52,474,238
Parent Company [Member]	'	'	'	'	'	'	'	'	'	'	'
General and administrative expenses	'	'	'	'	'	'	'	'	4,196	4,090	4,488
Investment and other income	'	'	'	'	'	'	'	'	983	19,921	-8,790
Interest Expense	'	'	'	'	'	'	'	'	-22,623	-15,757	-15,494
Earnings (loss) before income taxes	'	'	'	'	'	'	'	'	-25,836	74	-28,772
Income tax expense	'	'	'	'	'	'	'	'	-15,191	-9,668	-12,825
Net earnings (loss) before equity in subsidiaries	'	'	'	'	'	'	'	'	-10,645	9,742	-15,947
Equity in earnings from subsidiaries	'	'	'	'	'	'	'	'	171,863	78,791	136,465
Net earnings attributable to Centene Corporation	'	'	'	'	'	'	'	'	$161,218	$88,533	$120,518
Basic earnings (loss) per common share (in dollars per share)	'	'	'	'	'	'	'	'	$2.98	$1.72	$2.40
Diluted earnings (loss) per common share (in dollars per share)	'	'	'	'	'	'	'	'	$2.87	$1.65	$2.30
Basic	'	'	'	'	'	'	'	'	54,126,545	51,509,366	50,198,954
Diluted	'	'	'	'	'	'	'	'	56,247,173	53,714,375	52,474,238

Condensed_Financial_Informatio5

Condensed Financial Information Of Registrant (Condensed Statements Of Cash Flows) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash provided by operating activities	$382,526	$278,691	$261,696
Purchases of investments	-790,653	-695,687	-318,397
Sales and maturities of investments	579,161	589,921	267,404
Acquisitions, net of cash required	-62,773	0	-4,375
Net cash used in investing activities	-342,100	-187,910	-129,076
Proceeds from borrowings	180,000	400,500	419,183
Payment of long-term debt and notes payable	-41,593	-218,234	-416,283
Proceeds from exercise of stock options	8,983	15,912	15,815
Common stock offering	15,225	0	0
Common stock repurchases	-19,779	-12,741	-7,809
Debt issue costs	-3,589	-3,623	-9,242
Purchase of noncontrolling interest	0	-14,429	0
Excess tax benefits from stock compensation	6,380	10,996	4,435
Net cash provided by financing activities	153,695	179,473	6,912
Net (decrease) increase in cash and cash equivalents	194,121	270,254	139,532
Cash and cash equivalents, beginning of period	843,952	573,698	434,166
Cash and cash equivalents, end of period	1,038,073	843,952	573,698
Parent Company [Member]	'	'	'
Cash provided by operating activities	302,242	327,940	72,754
Net dividends from and capital contributions to subsidiaries	-417,734	-539,575	-50,581
Purchases of investments	12,518	-7,320	-21,915
Sales and maturities of investments	10,252	30,000	11,111
Acquisitions, net of cash required	67,070	0	-1,773
Net cash used in investing activities	-487,070	-516,895	-63,158
Proceeds from borrowings	180,000	400,500	419,183
Payment of long-term debt and notes payable	30,000	-215,000	-413,644
Proceeds from exercise of stock options	8,983	15,912	15,815
Common stock offering	15,225	0	0
Common stock repurchases	19,779	-12,741	-7,809
Debt issue costs	3,589	-3,623	-9,242
Contributions from noncontrolling interest	8,069	1,092	813
Purchase of noncontrolling interest	0	-14,429	0
Excess tax benefits from stock compensation	6,380	10,996	4,435
Net cash provided by financing activities	165,289	182,707	9,551
Net (decrease) increase in cash and cash equivalents	-19,539	-6,248	19,147
Cash and cash equivalents, beginning of period	22,279	28,527	9,380
Cash and cash equivalents, end of period	$2,740	$22,279	$28,527

Basis_Of_Presentation_And_Sign1

Basis Of Presentation And Significant Accounting Policies (Details) (Parent Company [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Parent Company [Member]	'	'	'
Cash Flows Received By Parent From Unrestricted Subsidiaries	$312,887	$318,198	$88,701

Dividends_Details

Dividends (Details) (Parent Company [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Parent Company [Member]	'	'	'
Cash Dividends Paid to Parent Company by Unconsolidated Subsidiaries	$20,500	$29,000	$69,100

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Subsequent Events [Abstract]	'	'
Business Combination, Consideration Transferred	$200,000	$142,495
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	2,243,217	'