Centene (CNC) 10-Q 22 Jul 14 2014 Q2 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	6 Months Ended
	Jun. 30, 2014	Jul. 11, 2014
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-Q	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	58,585,192

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents of continuing operations	$1,199,784	$974,304
Cash and cash equivalents of discontinued operations	59,013	63,769
Total cash and cash equivalents	1,258,797	1,038,073
Premium and related receivables	610,969	428,570
Short-term investments	127,348	102,126
Other current assets	313,946	217,661
Other current assets of discontinued operations	13,826	13,743
Total current assets	2,324,886	1,800,173
Long-term investments	996,965	791,900
Restricted deposits	78,442	46,946
Property, software and equipment, net	423,905	395,407
Goodwill	642,613	348,432
Intangible assets, net	81,359	48,780
Other long-term assets	107,967	59,357
Long term assets of discontinued operations	26,430	38,305
Total assets	4,682,567	3,529,300
Current liabilities:	'	'
Medical claims liability	1,394,115	1,111,709
Accounts payable and accrued expenses	670,343	375,862
Unearned revenue	22,472	38,191
Current portion of long-term debt	6,135	3,065
Current liabilities of discontinued operations	24,642	30,294
Total current liabilities	2,117,707	1,559,121
Long-term debt	884,890	665,697
Other long-term liabilities	73,897	60,015
Long term liabilities of discontinued operations	451	1,028
Total liabilities	3,076,945	2,285,861
Commitments and contingencies	'	'
Redeemable noncontrolling interest	119,671	0
Stockholders' equity:	'	'
Common stock, $.001 par value; authorized 200,000,000 shares; 61,265,156 issued and 57,837,919 outstanding at June 30, 2014, and 58,673,215 issued and 55,319,239 outstanding at December 31, 2013	61	59
Additional paid-in capital	754,637	594,326
Accumulated other comprehensive income:	'	'
Unrealized (loss) gain on investments, net of tax	2,214	-2,620
Retained earnings	813,765	731,919
Treasury stock, at cost (3,427,237 and 3,353,976 shares, respectively)	-94,512	-89,643
Total Centene stockholders' equity	1,476,165	1,234,041
Noncontrolling interest	9,786	9,398
Total stockholders' equity	1,485,951	1,243,439
Total liabilities and stockholders' equity	$4,682,567	$3,529,300

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Stockholders' equity	'	'
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized (in shares)	200,000,000	100,000,000
Common stock, shares issued (in shares)	61,265,156	58,673,215
Common stock, shares outstanding (in shares)	57,837,919	55,319,239
Treasury stock, at cost (in shares)	3,427,237	3,353,976

Consolidated_Statements_Of_Ope

Consolidated Statements Of Operations (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues:	'	'	'	'
Premium	$3,331,058	$2,413,312	$6,401,945	$4,801,951
Service	410,029	105,599	691,203	138,793
Premium and service revenues	3,741,087	2,518,911	7,093,148	4,940,744
Premium tax and health insurer fee	282,613	91,628	390,440	195,277
Total revenues	4,023,700	2,610,539	7,483,588	5,136,021
Expenses:	'	'	'	'
Medical costs	2,960,101	2,134,283	5,702,554	4,288,829
Cost of services	365,888	93,300	608,172	118,365
General and administrative expenses	321,042	223,459	616,554	426,755
Premium tax expense	252,669	90,760	330,947	193,735
Health insurer fee expense	31,328	0	62,655	0
Total operating expenses	3,931,028	2,541,802	7,320,882	5,027,684
Earnings from operations	92,672	68,737	162,706	108,337
Other income (expense):	'	'	'	'
Investment and other income	7,252	4,078	11,976	8,342
Interest expense	-8,604	-7,033	-15,627	-13,658
Earnings from continuing operations, before income tax expense	91,320	65,782	159,055	103,021
Income tax expense	44,874	25,966	79,429	40,657
Earnings from continuing operations, net of income tax expense	46,446	39,816	79,626	62,364
Discontinued operations, net of income tax expense (benefit)	1,680	-805	847	-442
Net earnings	48,126	39,011	80,473	61,922
Noncontrolling interest	-737	-473	-1,373	-564
Net earnings attributable to Centene Corporation	48,863	39,484	81,846	62,486
Earnings from continuing operations, net of income tax expense, attributable to Centene Corporation	$47,183	$40,289	$80,999	$62,928
Basic [Abstract]	'	'	'	'
Continuing operations	$0.82	$0.74	$1.41	$1.18
Discontinued operations	$0.03	($0.02)	$0.01	($0.01)
Basic earnings per common share	$0.85	$0.72	$1.42	$1.17
Diluted [Abstract]	'	'	'	'
Continuing operations	$0.79	$0.71	$1.36	$1.14
Discontinued operations	$0.03	($0.01)	$0.01	($0.01)
Diluted earnings per common share	$0.82	$0.70	$1.37	$1.13
Weighted Average Number of Common Shares Outstanding	'	'	'	'
Basic	57,758,683	54,529,036	57,622,039	53,449,077
Diluted	59,717,258	56,601,660	59,547,420	55,448,396

Consolidated_Statements_Of_Ope1

Consolidated Statements Of Operations Consolidated Statements of Operations (Parenthetical) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Consolidated Statements of Operations [Abstract]	'	'	'	'
Discontinued Operation, Tax Effect of Discontinued Operation	$1,461	($698)	$1,453	($350)

Consolidated_Statement_Of_Comp

Consolidated Statement Of Comprehensive Earnings (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net earnings (loss)	$48,126	$39,011	$80,473	$61,922
Reclassification adjustment, net of tax	29	-27	-709	-162
Change in unrealized (loss) gain on investments, net of tax	2,799	-8,934	5,543	-9,088
Other comprehensive earnings (loss)	2,828	-8,961	4,834	-9,250
Comprehensive earnings (loss)	50,954	30,050	85,307	52,672
Comprehensive earnings (loss) attributable to noncontrolling interest	-737	-473	-1,373	-564
Comprehensive earnings (loss) attributable to Centene Corporation	$51,691	$30,523	$86,680	$53,236

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 (Loss) [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, 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	'
Comprehensive Earnings:	'	'	'	'	'	'	'
Net Income (Loss) including amount attributable to nonredeemable noncontrolling interest	82,234	'	'	'	81,846	'	388
Change in unrealized investment gain, net of $2,722 tax	4,834	'	'	4,834	'	'	'
Comprehensive earnings (loss)	87,068	'	'	'	'	'	'
Common stock issued for acquisition	132,371	2	132,369	'	'	'	'
Common stock issued for acquisition (in shares)	2,243,217	2,243,217	'	'	'	'	'
Common stock issued for employee benefit plans	4,077	0	4,077	'	'	'	'
Common stock issued for employee benefit plans (in shares)	'	348,724	'	'	'	'	'
Common stock repurchases	-4,869	'	'	'	'	-4,869	'
Common stock repurchases (in shares)	'	'	'	'	'	73,261	'
Stock compensation expense	22,750	'	22,750	'	'	'	'
Excess tax benefits from stock compensation	1,115	'	1,115	'	'	'	'
Balance at Jun. 30, 2014	$1,485,951	$61	$754,637	$2,214	$813,765	($94,512)	$9,786
Balance (in shares) at Jun. 30, 2014	57,837,919	61,265,156	'	'	'	3,427,237	'

Consolidated_Statement_Of_Stoc1

Consolidated Statement Of Stockholders' Equity (Parenthetical) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Consolidated Statement of Stockholders' Equity (Parenthetical) [Abstract]	'
Tax on unrealized investment (loss) gain	$2,722

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:	'	'
Net earnings (loss)	$80,473	$61,922
Adjustments to reconcile net earnings (loss) to net cash provided by (used in) operating activities	'	'
Depreciation and amortization	42,101	32,928
Stock compensation expense	22,750	16,955
Deferred income taxes	-11,258	10,715
Changes in assets and liabilities	'	'
Premium and related receivables	-160,714	-71,230
Other current assets	28,826	-35,879
Other assets	-28,733	-38,191
Medical claims liabilites	284,134	111,625
Unearned revenue	-18,066	-12,068
Accounts payable and accrued expenses	160,128	-1,488
Other operating activities	12,248	5,650
Net cash provided by (used in) operating activities	411,889	80,939
Cash flows from investing activities:	'	'
Capital expenditures	-41,568	-30,057
Purchases of investments	-475,347	-537,590
Sales and maturities of investments	221,342	358,971
Investments in acquisitions, net of cash acquired	-94,004	-66,832
Net cash used in investing activities	-389,577	-275,508
Cash flows from financing activities:	'	'
Proceeds from exercise of stock options	3,670	3,867
Proceeds from borrowings	1,145,000	30,000
Payment of long-term debt	-945,892	-10,118
Proceeds from stock offering	0	15,239
Excess tax benefits from stock compensation	1,115	1,113
Common stock repurchases	-4,869	-1,105
Contribution from noncontrolling interest	5,407	3,920
Debt issue costs	-6,019	-3,587
Net cash provided by financing activities	198,412	39,329
Net decrease in cash and cash equivalents	220,724	-155,240
Cash and cash equivalents, beginning of period	1,038,073	843,952
Cash and cash equivalents, end of period	1,258,797	688,712
Supplemental disclosures of cash flow information:	'	'
Interest paid	16,439	15,170
Income taxes paid	110,118	21,694
Equity issued in connection with acquisition	$132,371	$75,438

Basis_Of_Presentation

Basis Of Presentation	6 Months Ended
	Jun. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis Of Presentation	'
	Basis of Presentation
	The accompanying interim financial statements have been prepared under the presumption that users of the interim financial information have either read or have access to the audited financial statements included in the Form 10-K for the fiscal year ended December 31, 2013.  The unaudited interim financial statements herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission.  Accordingly, footnote disclosures which would substantially duplicate the disclosures contained in the December 31, 2013 audited financial statements have been omitted from these interim financial statements where appropriate.  In the opinion of management, these financial statements reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair presentation of the results of the interim periods presented.
	Certain 2013 amounts in the notes to the consolidated financial statements have been reclassified to conform to the 2014 presentation. These reclassifications have no effect on net earnings or stockholders’ equity as previously reported.

Acquisition_Notes

Acquisition (Notes)	6 Months Ended
	Jun. 30, 2014
Business Combinations [Abstract]	'
Acquisition	'
	Acquisition: U.S. Medical Management
	In January 2014, the Company acquired 68% of U.S. Medical Management, LLC (USMM), a management services organization and provider of in-home health services for high acuity populations, for $213,664 in total consideration. The transaction consideration was financed through a combination of $132,686 of Centene common stock and $80,978 of cash.
	The total fair value of 100% of USMM on the date of acquisition was $329,689 ($213,664 for the Company's interest and $116,025 for the redeemable noncontrolling interest). The Company's preliminary allocation of fair value resulted in goodwill of $294,074 and other identifiable intangible assets of $40,170. Approximately 70% of the goodwill is deductible for income tax purposes. The Company has not finalized the allocation of the fair value of assets and liabilities. The acquisition is recorded in the Specialty Services segment.
	In connection with the acquisition, the Company entered into call and put agreements with the noncontrolling interest holder to purchase the noncontrolling interest at a later date. Under these agreements, the Company may purchase or be required to purchase up to the total remaining interests in USMM over a period beginning in 2015 and continuing through 2017. Under certain circumstances, the agreements may be extended through 2020. At the Company’s sole option, up to 50% of the consideration to be issued for the purchase of the additional interests under these agreements may be funded with shares of the Company's common stock.
	As a result of the put option agreement, the noncontrolling interest is considered redeemable and is classified in the Redeemable Noncontrolling Interest section of the consolidated balance sheet. The noncontrolling interest was initially measured at fair value using the binomial lattice model as of the acquisition date. The Company has elected to accrete changes in the redemption value through additional paid-in capital over the period from the date of issuance to the earliest redemption date following the effective interest method.
	A reconciliation of the changes in the Redeemable Noncontrolling Interest is as follows:
	Balance, December 31, 2013	$	—
	Fair value of noncontrolling interest at acquisition	116,025
	Contribution from noncontrolling interest	5,407
	Net losses attributable to noncontrolling interest	(1,761		)
	Balance, June 30, 2014	$	119,671

Discontinued_Operations_Notes

Discontinued Operations (Notes)	6 Months Ended
	Jun. 30, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Disposal Groups, Including Discontinued Operations, Disclosure	'
	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 allowed 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. Refer to Note 11, Contingencies, in the Notes to the Consolidated Financial Statements for further information regarding litigation between the Company and the Cabinet.
	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 six months ended June 30, 2014, the Company received $8,000 of dividends from KSHP. KSHP had remaining statutory capital of approximately $72,400 at June 30, 2014, which, subject to future dividends, will be transferred to unregulated cash upon regulatory approval.
	Operating results for the discontinued operations are as follows:
		Three Months Ended June 30,					Six Months Ended June 30,
		2014		2013			2014		2013
	Revenues	$	—	$	115,407		$	—	$	235,816
	Earnings (loss) before income taxes	3,141		(1,503		)	2,300		(792		)
	Net earnings (loss)	1,680		(805		)	847		(442		)
	The net earnings from discontinued operations for the three and six months ended June 30, 2014 includes $894 and $1,788, respectively, of health insurer fee expense based on 2013 premium.
	Assets and liabilities of the discontinued operations are as follows:
		June 30, 2014		December 31, 2013
	Current assets	$	72,839	$	77,512
	Long term investments and restricted deposits	26,430		38,305
	Assets of discontinued operations	$	99,269	$	115,817
	Medical claims liability	$	14,251	$	27,637
	Accounts payable and accrued expenses	10,391		2,657
	Other liabilities	451		1,028
	Liabilities of discontinued operations	$	25,093	$	31,322

ShortTerm_And_LongTerm_Investm

Short-Term And Long-Term Investments And Restricted Deposits	6 Months Ended
	Jun. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Short-Term And Long-Term Investments And Restricted Deposits	'
	Short-term and Long-term Investments, Restricted Deposits
	Short-term and long-term investments and restricted deposits by investment type consist of the following:
		June 30, 2014										December 31, 2013
		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	$	325,602		$	424	$	(3,349	)	$	322,677	$	246,085		$	245	$	(7,494	)	$	238,836
	Corporate securities	395,427			4,087		(166		)	399,348		293,912			2,782		(608		)	296,086
	Restricted certificates of deposit	5,892			—		—			5,892		5,891			—		—			5,891
	Restricted cash equivalents	57,608			—		—			57,608		26,642			—		—			26,642
	Municipal securities:
	General obligation	38,950			480		(22		)	39,408		54,003			555		(136		)	54,422
	Pre-refunded	8,486			59		(10		)	8,535		10,835			82		—			10,917
	Revenue	68,871			571		(42		)	69,400		68,801			545		(292		)	69,054
	Variable rate demand notes	18,000			—		—			18,000		28,575			—		—			28,575
	Asset backed securities	179,418			636		(69		)	179,985		138,803			579		(332		)	139,050
	Mortgage backed securities	47,113			1,157		—			48,270		33,974			—		(83		)	33,891
	Cost and equity method investments	38,087			—		—			38,087		22,239			—		—			22,239
	Life insurance contracts	15,545			—		—			15,545		15,369			—		—			15,369
	Total	$	1,198,999		$	7,414	$	(3,658	)	$	1,202,755	$	945,129		$	4,788	$	(8,945	)	$	940,972
	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 June 30, 2014, 53% 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, 65% were rated AA-/Aa3 or higher, and 93% were rated A-/A3 or higher.  At June 30, 2014, 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:
		June 30, 2014										December 31, 2013
		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	$	(18	)	$	11,987	$	(3,331	)	$	179,105	$	(6,188	)	$	172,365	$	(1,307	)	$	26,454
	Corporate securities	(149		)	56,343		(17		)	985		(400		)	52,725		(207		)	5,020
	Municipal securities:
	General obligation	—			—		(22		)	3,476		(72		)	3,480		(63		)	2,426
	Pre-refunded	(10		)	1,034		—			—		—			—		—			—
	Revenue	—			—		(42		)	3,413		(292		)	27,789		—			—
	Asset backed securities	—			—		—			—		(333		)	37,689		—			—
	Mortgage backed securities	(3		)	9,969		(66		)	15,706		(83		)	33,891		—			—
	Total	$	(180	)	$	79,333	$	(3,478	)	$	202,685	$	(7,368	)	$	327,939	$	(1,577	)	$	33,900
	As of June 30, 2014, the gross unrealized losses were generated from 51 positions out of a total of 323 positions.  The change 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:
		June 30, 2014										December 31, 2013
		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	$	126,496		$	127,348	$	60,665		$	60,665	$	101,537		$	102,126	$	40,633		$	40,637
	One year through five years	855,731			859,409		17,770			17,777		609,755			610,589		6,301			6,309
	Five years through ten years	118,210			116,873		—			—		157,003			151,221		—			—
	Greater than ten years	20,127			20,683		—			—		29,900			30,090		—			—
	Total	$	1,120,564		$	1,124,313	$	78,435		$	78,442	$	898,195		$	894,026	$	46,934		$	46,946
	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	6 Months Ended
	Jun. 30, 2014
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 June 30, 2014, for assets and liabilities measured at fair value on a recurring basis:
		Level I		Level II		Level III		Total
	Assets
	Cash and cash equivalents	$	1,199,784	$	—	$	—	$	1,199,784
	Investments available for sale:
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	288,546	$	19,189	$	—	$	307,735
	Corporate securities	—		399,348		—		399,348
	Municipal securities:
	General obligation	—		39,408		—		39,408
	Pre-refunded	—		8,535		—		8,535
	Revenue	—		69,400		—		69,400
	Variable rate demand notes	—		18,000		—		18,000
	Asset backed securities	—		179,985		—		179,985
	Mortgage backed securities	—		48,270		—		48,270
	Total investments	$	288,546	$	782,135	$	—	$	1,070,681
	Restricted deposits available for sale:
	Cash and cash equivalents	$	57,608	$	—	$	—	$	57,608
	Certificates of deposit	5,892		—		—		5,892
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	14,942		—		—		14,942
	Total restricted deposits	$	78,442	$	—	$	—	$	78,442
	Other long-term assets: Interest rate swap agreements	$	—	$	9,506	$	—	$	9,506
	Total assets at fair value	$	1,566,772	$	791,641	$	—	$	2,358,413
	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 agreements	$	—	$	9,576	$	—	$	9,576
	Total assets at fair value	$	1,233,435	$	653,809	$	—	$	1,887,244
	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 June 30, 2014, there were $14,161 of transfers from Level I to Level II and $1,214 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 $53,632 and $37,608 as of June 30, 2014 and December 31, 2013, respectively.

Debt

Debt	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Debt	'
	Debt
	Debt consists of the following:
		June 30, 2014			December 31, 2013
	Senior notes, at par	$	725,000		$	425,000
	Unamortized premium on senior notes	5,166			6,052
	Fair value of interest rate swap agreements	9,506			9,576
	Senior notes	739,672			440,628
	Revolving credit agreement	70,000			150,000
	Mortgage notes payable	71,437			72,785
	Capital leases and other	9,916			5,349
	Total debt	891,025			668,762
	Less current portion	(6,135		)	(3,065		)
	Long-term debt	$	884,890		$	665,697
	Senior Notes
	In May 2011, the Company issued $250,000 non-callable 5.75% Senior Notes due June 1, 2017 ($250,000 Notes) at a discount to yield 6%. In connection with the May 2011 issuance, the Company entered into interest rate swap agreements for a notional amount of $250,000. Gains and losses due to changes in the fair value of the interest rate swap agreements 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 June 30, 2014, the fair value of the interest rate swap agreements increased the fair value of the notes by $8,935 and the variable interest rate of the swap agreements was 3.73%.
	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 June 30, 2014, the total net unamortized debt premium on the $250,000 Notes and $175,000 Add-on Notes was $5,166.
	In April 2014, the Company issued $300,000 4.75% Senior Notes due May 15, 2022 ($300,000 Notes) at par. In connection with the April 2014 issuance, the Company entered into interest rate swap agreements for a notional amount of $300,000. Gains and losses due to changes in the fair value of the interest rate swap agreements completely offset changes in the fair value of the hedged portion of the underlying debt and are recorded as an adjustment to the $300,000 Notes. At June 30, 2014, the fair value of the interest rate swap agreements increased the fair value of the notes by $571 and the variable interest rate of the swap agreements was 2.52%.
	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), certain financial conditions are not met, or the Company does not carry $100,000 of unrestricted cash. As of June 30, 2014, the Company had $70,000 of borrowings outstanding under the agreement with a weighted average interest rate of 2.50%.
	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 to not exceed a maximum debt-to-EBITDA ratio of 3.0 to 1.0. As of June 30, 2014, there were no limitations on the availability under the revolving credit agreement as a result of the debt-to-EBITDA ratio.
	Letters of Credit & Surety Bonds
	The Company had outstanding letters of credit of $30,649 as of June 30, 2014, which were not part of the revolving credit facility.  The letters of credit bore interest at 0.46% as of June 30, 2014. The Company had outstanding surety bonds of $159,728 as of June 30, 2014.

Interest_Rate_Swap_Notes

Interest Rate Swap (Notes)	6 Months Ended
	Jun. 30, 2014
Interest Rate Swap [Abstract]	'
Interest Rate Swap [Text Block]	'
	Interest Rate Swap Agreements
	In May 2011, the Company entered into $250,000 notional amount of interest rate swap agreements (2011 Swap Agreements) that are scheduled to expire June 1, 2017. Under the 2011 Swap Agreements, the Company receives a fixed rate of 5.75% and pays a variable rate of the three month LIBOR plus 3.50% adjusted quarterly, which allows the Company to adjust $250,000 of its senior notes to a floating rate. At June 30, 2014, the variable rate was 3.73%.
	In April 2014, the Company entered into $300,000 notional amount of interest rate swap agreements (2014 Swap Agreements) that are scheduled to expire May 15, 2022. Under the 2014 Swap Agreements, the Company receives a fixed rate of 4.75% and pays a variable rate of the three month LIBOR plus 2.27% adjusted quarterly, which allows the Company to adjust $300,000 of its senior notes to a floating rate. At June 30, 2014, the variable rate was 2.52%.
	The 2011 and 2014 Swap Agreements are formally designated and qualify as fair value hedges. The 2011 and 2014 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 swap agreements 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 swap agreements and the hedged portion of the underlying debt both were recognized in interest expense in the Consolidated Statement of Operations. The Company does not hold or issue any derivative instrument for trading or speculative purposes.
	The fair values of the 2011 and 2014 Swap Agreements as of June 30, 2014 were assets of approximately $8,935 and $571, respectively and are included in other long term assets in the Consolidated Balance Sheet. The fair value of the 2011 and 2014 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_Notes

Stockholders' Equity (Notes)	6 Months Ended
	Jun. 30, 2014
Stockholders' Equity Attributable to Parent [Abstract]	'
Stockholders' Equity	'
	Stockholders' Equity
	In January 2014, the Company completed the acquisition of 68% of USMM and as a result, issued 2,243,217 shares of Centene common stock to the selling stockholders.

Earnings_Loss_Per_Share

Earnings (Loss) Per Share	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Earnings (Loss) Per Share	'
	Earnings Per Share
	The following table sets forth the calculation of basic and diluted net earnings per common share:
		Three Months Ended June 30,					Six Months Ended June 30,
		2014		2013			2014		2013
	Earnings attributable to Centene Corporation:
	Earnings from continuing operations, net of tax	$	47,183	$	40,289		$	80,999	$	62,928
	Discontinued operations, net of tax	1,680		(805		)	847		(442		)
	Net earnings	$	48,863	$	39,484		$	81,846	$	62,486
	Shares used in computing per share amounts:
	Weighted average number of common shares outstanding	57,758,683		54,529,036			57,622,039		53,449,077
	Common stock equivalents (as determined by applying the treasury stock method)	1,958,575		2,072,624			1,925,381		1,999,319
	Weighted average number of common shares and potential dilutive common shares outstanding	59,717,258		56,601,660			59,547,420		55,448,396
	Net earnings (loss) per common share attributable to Centene Corporation:
	Basic:
	Continuing operations	$	0.82	$	0.74		$	1.41	$	1.18
	Discontinued operations	0.03		(0.02		)	0.01		(0.01		)
	Basic earnings per common share	$	0.85	$	0.72		$	1.42	$	1.17
	Diluted:
	Continuing operations	$	0.79	$	0.71		$	1.36	$	1.14
	Discontinued operations	0.03		(0.01		)	0.01		(0.01		)
	Diluted earnings per common share	$	0.82	$	0.7		$	1.37	$	1.13
	The calculation of diluted earnings per common share for the three and six months ended June 30, 2014 excludes the impact of 51,855 shares and 55,544 shares, respectively, related to anti-dilutive stock options, restricted stock and restricted stock units. The calculation of diluted earnings per common share for the three and six months ended June 30, 2013 excludes the impact of 35,094 shares and 68,809 shares, respectively, related to anti-dilutive stock options, restricted stock and restricted stock units.

Segment_Information

Segment Information	6 Months Ended
	Jun. 30, 2014
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.
	Segment information for the three months ended June 30, 2014, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	3,224,849	$	516,238	$	—		$	3,741,087
	Premium and service revenues from internal customers	13,789		675,825		(689,614		)	—
	Total premium and service revenues	$	3,238,638	$	1,192,063	$	(689,614	)	$	3,741,087
	Earnings from operations	$	63,821	$	28,851	$	—		$	92,672
	Segment information for the three months ended June 30, 2013, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	2,324,750	$	194,161	$	—		$	2,518,911
	Premium and service revenues from internal customers	10,292		523,154		(533,446		)	—
	Total premium and service revenues	$	2,335,042	$	717,315	$	(533,446	)	$	2,518,911
	Earnings from operations	$	45,601	$	23,136	$	—		$	68,737
	Segment information for the six months ended June 30, 2014, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	6,194,570	$	898,578	$	—		$	7,093,148
	Premium and service revenues from internal customers	26,614		1,314,741		(1,341,355		)	—
	Total premium and service revenues	$	6,221,184	$	2,213,319	$	(1,341,355	)	$	7,093,148
	Earnings from operations	$	107,951	$	54,755	$	—		$	162,706
	Segment information for the six months ended June 30, 2013, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	4,621,199	$	319,545	$	—		$	4,940,744
	Premium and service revenues from internal customers	20,345		1,050,607		(1,070,952		)	—
	Total premium and service revenues	$	4,641,544	$	1,370,152	$	(1,070,952	)	$	4,940,744
	Earnings from operations	$	54,860	$	53,477	$	—		$	108,337

Contingencies

Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Contingencies	'
	Contingencies
	In October 2012, the Company notified the Cabinet that it was exercising a contractual right that it believes allows the Company to terminate its Medicaid managed care contract with the 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. In March 2014, Kentucky Spirit received a demand letter from the Commonwealth seeking damages to reimburse the Commonwealth for its alleged incurred and expected losses, expenses, transition costs and other damages for the period July 6, 2013 until July 5, 2014. The letter stated that the Commonwealth is seeking damages only on behalf of the Commonwealth, not the federal Centers for Medicare and Medicaid Services (CMS). In June 2014, the Commonwealth informed the Kentucky Department of Insurance that its expenditures due to Kentucky's Spirit's departure range from $28,000 to $40,000 plus interest, and that the associated CMS expenditures range from $92,000 to $134,000. Kentucky Spirit disputes the Commonwealth's alleged damages, is pursuing its own 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 June 30, 2014.  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 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.

Subsequent_Events_Notes

Subsequent Events (Notes)	6 Months Ended
	Jun. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events [Text Block]	'
	12. Subsequent Events
	In July 2014, the Company completed the transaction whereby Community Health Solutions of America, Inc. assigned its contract with the Louisiana Department of Health and Hospitals under the Bayou Health Shared Savings Program to the Company's subsidiary, Louisiana Healthcare Connections (LHC). The purchase price is expected to be between approximately $110,000 and $140,000. Initial consideration of approximately $72,100 consists of a cash payment of $14,100 paid at signing and approximately $58,000 of common stock (746,369 shares) issued at closing. The remaining purchase price will be paid in cash in multiple steps and will be finalized based on membership retained by LHC in the first quarter of 2015.
	In July 2014, the Company purchased a noncontrolling interest in Ribera Salud S.A. (Ribera Salud), a Spanish health management group for approximately $16,000, subject to working capital adjustments. Centene will be a 50% joint shareholder with Ribera Salud's remaining investor, Banco Sabadell. The Company will account for its investment using the equity method of accounting. Upon closing, the Company executed letters of credit for approximately $65,000, or €48,000, representing its proportional share of the letters of credit issued to support Ribera Salud’s outstanding debt.

Acquisition_Redeemable_Noncont

Acquisition Redeemable Noncontrolling Interest (Tables)	6 Months Ended
	Jun. 30, 2014
Redeemable Noncontrolling Interest [Line Items]	'
Redeemable Noncontrolling Interest [Table Text Block]	'
	A reconciliation of the changes in the Redeemable Noncontrolling Interest is as follows:
	Balance, December 31, 2013	$	—
	Fair value of noncontrolling interest at acquisition	116,025
	Contribution from noncontrolling interest	5,407
	Net losses attributable to noncontrolling interest	(1,761		)
	Balance, June 30, 2014	$	119,671

Discontinued_Operations_Tables

Discontinued Operations (Tables)	6 Months Ended
	Jun. 30, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	'
	Operating results for the discontinued operations are as follows:
		Three Months Ended June 30,					Six Months Ended June 30,
		2014		2013			2014		2013
	Revenues	$	—	$	115,407		$	—	$	235,816
	Earnings (loss) before income taxes	3,141		(1,503		)	2,300		(792		)
	Net earnings (loss)	1,680		(805		)	847		(442		)
	The net earnings from discontinued operations for the three and six months ended June 30, 2014 includes $894 and $1,788, respectively, of health insurer fee expense based on 2013 premium.
	Assets and liabilities of the discontinued operations are as follows:
		June 30, 2014		December 31, 2013
	Current assets	$	72,839	$	77,512
	Long term investments and restricted deposits	26,430		38,305
	Assets of discontinued operations	$	99,269	$	115,817
	Medical claims liability	$	14,251	$	27,637
	Accounts payable and accrued expenses	10,391		2,657
	Other liabilities	451		1,028
	Liabilities of discontinued operations	$	25,093	$	31,322

ShortTerm_And_LongTerm_Investm1

Short-Term And Long-Term Investments And Restricted Deposits (Tables)	6 Months Ended
	Jun. 30, 2014
Investments, Debt and Equity Securities [Abstract]	'
Short-Term And Long-Term Investments And Restricted Deposits By Investment Type	'
	Short-term and Long-term Investments, Restricted Deposits
	Short-term and long-term investments and restricted deposits by investment type consist of the following:
		June 30, 2014										December 31, 2013
		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	$	325,602		$	424	$	(3,349	)	$	322,677	$	246,085		$	245	$	(7,494	)	$	238,836
	Corporate securities	395,427			4,087		(166		)	399,348		293,912			2,782		(608		)	296,086
	Restricted certificates of deposit	5,892			—		—			5,892		5,891			—		—			5,891
	Restricted cash equivalents	57,608			—		—			57,608		26,642			—		—			26,642
	Municipal securities:
	General obligation	38,950			480		(22		)	39,408		54,003			555		(136		)	54,422
	Pre-refunded	8,486			59		(10		)	8,535		10,835			82		—			10,917
	Revenue	68,871			571		(42		)	69,400		68,801			545		(292		)	69,054
	Variable rate demand notes	18,000			—		—			18,000		28,575			—		—			28,575
	Asset backed securities	179,418			636		(69		)	179,985		138,803			579		(332		)	139,050
	Mortgage backed securities	47,113			1,157		—			48,270		33,974			—		(83		)	33,891
	Cost and equity method investments	38,087			—		—			38,087		22,239			—		—			22,239
	Life insurance contracts	15,545			—		—			15,545		15,369			—		—			15,369
	Total	$	1,198,999		$	7,414	$	(3,658	)	$	1,202,755	$	945,129		$	4,788	$	(8,945	)	$	940,972
Fair Value Of Available-For-Sale Investments With Gross Unrealized Losses By Investment Type And Length Of Time	'
	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:
		June 30, 2014										December 31, 2013
		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	$	(18	)	$	11,987	$	(3,331	)	$	179,105	$	(6,188	)	$	172,365	$	(1,307	)	$	26,454
	Corporate securities	(149		)	56,343		(17		)	985		(400		)	52,725		(207		)	5,020
	Municipal securities:
	General obligation	—			—		(22		)	3,476		(72		)	3,480		(63		)	2,426
	Pre-refunded	(10		)	1,034		—			—		—			—		—			—
	Revenue	—			—		(42		)	3,413		(292		)	27,789		—			—
	Asset backed securities	—			—		—			—		(333		)	37,689		—			—
	Mortgage backed securities	(3		)	9,969		(66		)	15,706		(83		)	33,891		—			—
	Total	$	(180	)	$	79,333	$	(3,478	)	$	202,685	$	(7,368	)	$	327,939	$	(1,577	)	$	33,900
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:
		June 30, 2014										December 31, 2013
		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	$	126,496		$	127,348	$	60,665		$	60,665	$	101,537		$	102,126	$	40,633		$	40,637
	One year through five years	855,731			859,409		17,770			17,777		609,755			610,589		6,301			6,309
	Five years through ten years	118,210			116,873		—			—		157,003			151,221		—			—
	Greater than ten years	20,127			20,683		—			—		29,900			30,090		—			—
	Total	$	1,120,564		$	1,124,313	$	78,435		$	78,442	$	898,195		$	894,026	$	46,934		$	46,946

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements By Level For Assets And Liabilities Measured At Fair Value On A Recurring Basis	'
	The following table summarizes fair value measurements by level at June 30, 2014, for assets and liabilities measured at fair value on a recurring basis:
		Level I		Level II		Level III		Total
	Assets
	Cash and cash equivalents	$	1,199,784	$	—	$	—	$	1,199,784
	Investments available for sale:
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	288,546	$	19,189	$	—	$	307,735
	Corporate securities	—		399,348		—		399,348
	Municipal securities:
	General obligation	—		39,408		—		39,408
	Pre-refunded	—		8,535		—		8,535
	Revenue	—		69,400		—		69,400
	Variable rate demand notes	—		18,000		—		18,000
	Asset backed securities	—		179,985		—		179,985
	Mortgage backed securities	—		48,270		—		48,270
	Total investments	$	288,546	$	782,135	$	—	$	1,070,681
	Restricted deposits available for sale:
	Cash and cash equivalents	$	57,608	$	—	$	—	$	57,608
	Certificates of deposit	5,892		—		—		5,892
	U.S. Treasury securities and obligations of U.S. government corporations and agencies	14,942		—		—		14,942
	Total restricted deposits	$	78,442	$	—	$	—	$	78,442
	Other long-term assets: Interest rate swap agreements	$	—	$	9,506	$	—	$	9,506
	Total assets at fair value	$	1,566,772	$	791,641	$	—	$	2,358,413
	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 agreements	$	—	$	9,576	$	—	$	9,576
	Total assets at fair value	$	1,233,435	$	653,809	$	—	$	1,887,244

Debt_Tables

Debt (Tables)	6 Months Ended
	Jun. 30, 2014
Debt Disclosure [Abstract]	'
Schedule Of Debt	'
	Debt consists of the following:
		June 30, 2014			December 31, 2013
	Senior notes, at par	$	725,000		$	425,000
	Unamortized premium on senior notes	5,166			6,052
	Fair value of interest rate swap agreements	9,506			9,576
	Senior notes	739,672			440,628
	Revolving credit agreement	70,000			150,000
	Mortgage notes payable	71,437			72,785
	Capital leases and other	9,916			5,349
	Total debt	891,025			668,762
	Less current portion	(6,135		)	(3,065		)
	Long-term debt	$	884,890		$	665,697

Earnings_Loss_Per_Share_Tables

Earnings (Loss) Per Share (Tables)	6 Months Ended
	Jun. 30, 2014
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:
		Three Months Ended June 30,					Six Months Ended June 30,
		2014		2013			2014		2013
	Earnings attributable to Centene Corporation:
	Earnings from continuing operations, net of tax	$	47,183	$	40,289		$	80,999	$	62,928
	Discontinued operations, net of tax	1,680		(805		)	847		(442		)
	Net earnings	$	48,863	$	39,484		$	81,846	$	62,486
	Shares used in computing per share amounts:
	Weighted average number of common shares outstanding	57,758,683		54,529,036			57,622,039		53,449,077
	Common stock equivalents (as determined by applying the treasury stock method)	1,958,575		2,072,624			1,925,381		1,999,319
	Weighted average number of common shares and potential dilutive common shares outstanding	59,717,258		56,601,660			59,547,420		55,448,396
	Net earnings (loss) per common share attributable to Centene Corporation:
	Basic:
	Continuing operations	$	0.82	$	0.74		$	1.41	$	1.18
	Discontinued operations	0.03		(0.02		)	0.01		(0.01		)
	Basic earnings per common share	$	0.85	$	0.72		$	1.42	$	1.17
	Diluted:
	Continuing operations	$	0.79	$	0.71		$	1.36	$	1.14
	Discontinued operations	0.03		(0.01		)	0.01		(0.01		)
	Diluted earnings per common share	$	0.82	$	0.7		$	1.37	$	1.13

Segment_Information_Tables

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2014
Segment Reporting [Abstract]	'
Segment Information	'
	Segment information for the three months ended June 30, 2014, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	3,224,849	$	516,238	$	—		$	3,741,087
	Premium and service revenues from internal customers	13,789		675,825		(689,614		)	—
	Total premium and service revenues	$	3,238,638	$	1,192,063	$	(689,614	)	$	3,741,087
	Earnings from operations	$	63,821	$	28,851	$	—		$	92,672
	Segment information for the three months ended June 30, 2013, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	2,324,750	$	194,161	$	—		$	2,518,911
	Premium and service revenues from internal customers	10,292		523,154		(533,446		)	—
	Total premium and service revenues	$	2,335,042	$	717,315	$	(533,446	)	$	2,518,911
	Earnings from operations	$	45,601	$	23,136	$	—		$	68,737
	Segment information for the six months ended June 30, 2014, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	6,194,570	$	898,578	$	—		$	7,093,148
	Premium and service revenues from internal customers	26,614		1,314,741		(1,341,355		)	—
	Total premium and service revenues	$	6,221,184	$	2,213,319	$	(1,341,355	)	$	7,093,148
	Earnings from operations	$	107,951	$	54,755	$	—		$	162,706
	Segment information for the six months ended June 30, 2013, follows:
		Managed Care		Specialty		Eliminations			Consolidated
				Services					Total
	Premium and service revenues from external customers	$	4,621,199	$	319,545	$	—		$	4,940,744
	Premium and service revenues from internal customers	20,345		1,050,607		(1,070,952		)	—
	Total premium and service revenues	$	4,641,544	$	1,370,152	$	(1,070,952	)	$	4,940,744
	Earnings from operations	$	54,860	$	53,477	$	—		$	108,337

Acquisition_Details

Acquisition (Details) (USD $)	1 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Business Combinations [Abstract]	'	'	'
Percentage of acquisition	68.00%	'	'
Business Combination, Consideration Transferred	$213,664	'	'
Common stock issued for acquisition	132,686	'	'
Payments to Acquire Businesses, Gross	80,978	'	'
Business Combination, Total Fair Value	329,689	'	'
Goodwill	294,074	642,613	348,432
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$40,170	'	'
BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductiblePercent	70.00%	'	'
Percent of future consideration issuable in shares	50.00%	'	'

Acquisition_Redeemable_Noncont1

Acquisition Redeemable Noncontrolling Interest (Details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jan. 31, 2014	Dec. 31, 2013
Redeemable Noncontrolling Interest [Line Items]	'	'	'
Redeemable Noncontrolling Interest, Equity, Fair Value	'	$116,025	'
Proceeds from Noncontrolling Interests	5,407	'	'
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest	-1,761	'	'
Redeemable Noncontrolling Interest, Equity, Carrying Amount	$119,671	'	$0

Discontinued_Operations_Discon

Discontinued Operations Discontinued Operations (Operating Results) (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Discontinued Operations and Disposal Groups [Abstract]	'	'	'	'
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries	$8,000	'	'	'
Health Insurer Fee Expense, from discontinued operations	894	'	1,788	'
Disposal Group, Including Discontinued Operation, Revenue	0	115,407	0	235,816
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	3,141	-1,503	2,300	-792
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$1,680	($805)	$847	($442)

Discontinued_Operations_Discon1

Discontinued Operations Discontinued Operations (Assets & Liabilities) (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'
Statutory capital and surplus	$72,400	'
Assets of Disposal Group, Including Discontinued Operation, Current	72,839	77,512
Disposal Group, Including Discontinued Operations, Long Term Investments and Restricted Deposits	26,430	38,305
Assets of Disposal Group, Including Discontinued Operation	99,269	115,817
Disposal Group, Including Discontinued Operations, Medical Claims Liability	14,251	27,637
Disposal Group, Including Discontinued Operation, Accounts Payable and Accrued Liabilities	10,391	2,657
Disposal Group, Including Discontinued Operation, Other Noncurrent Liabilities	451	1,028
Liabilities of Disposal Group, Including Discontinued Operation	$25,093	$31,322

ShortTerm_And_LongTerm_Investm2

Short-Term And Long-Term Investments And Restricted Deposits (Narrative) (Details)	Jun. 30, 2014
	positions
Investments, Debt and Equity Securities [Abstract]	'
Percentage of investments in securities recorded at fair value that carry a rating by Moody's or S&P of AAA/Aaa	53.00%
Percentage of investments in securities recorded at fair value that carry a rating by Moody's or S&P of AA-/Aa3 or higher	65.00%
Percentage of investments in securities recorded at fair value that carry a rating by Moody's or S&P of A-/A3 or higher	93.00%
Positions from which gross unrealized losses were generated	51
TotalUnrealizedInvestmentPositions	323

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 $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	$1,198,999	$945,129
Fair Value	1,202,755	940,972
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	7,414	4,788
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-3,658	-8,945
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	325,602	246,085
Fair Value	322,677	238,836
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	424	245
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-3,349	-7,494
Corporate Securities [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	395,427	293,912
Fair Value	399,348	296,086
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	4,087	2,782
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-166	-608
Restricted Certificates Of Deposit [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	5,892	5,891
Fair Value	5,892	5,891
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Restricted Cash Equivalents [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	57,608	26,642
Fair Value	57,608	26,642
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Municipal Securities, General Obligation [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	38,950	54,003
Fair Value	39,408	54,422
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	480	555
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-22	-136
Municipal Securities, Pre-Refunded [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	8,486	10,835
Fair Value	8,535	10,917
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	59	82
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-10	0
Municipal Securities, Revenue [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	68,871	68,801
Fair Value	69,400	69,054
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	571	545
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-42	-292
Municipal Securities, Variable Rate Demand Notes [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	18,000	28,575
Fair Value	18,000	28,575
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Asset Backed Securities [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	179,418	138,803
Fair Value	179,985	139,050
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	636	579
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-69	-332
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	47,113	33,974
Fair Value	48,270	33,891
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	1,157	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	-83
Cost And Equity Method Investments [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	38,087	22,239
Fair Value	38,087	22,239
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0	0
Life Insurance Contracts [Member]	'	'
Schedule Of Investments And Restricted Deposits By Type [Line Items]	'	'
Amortized Cost	15,545	15,369
Fair Value	15,545	15,369
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0	0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	$0	$0

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 $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months, Fair Value	$79,333	$327,939
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	3,478	1,577
12 Months or More, Fair Value	202,685	33,900
Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses Accumulated In Investments	-180	-7,368
U.S. Treasury Securities And Obligations Of U.S. Government Corporations And Agencies [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months, Fair Value	11,987	172,365
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	3,331	1,307
12 Months or More, Fair Value	179,105	26,454
Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses Accumulated In Investments	-18	-6,188
Corporate Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months, Fair Value	56,343	52,725
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	17	207
12 Months or More, Fair Value	985	5,020
Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses Accumulated In Investments	-149	-400
Municipal Securities, General Obligation [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months, Fair Value	0	3,480
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	22	63
12 Months or More, Fair Value	3,476	2,426
Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses Accumulated In Investments	0	-72
Municipal Securities, Pre-Refunded [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months, Fair Value	1,034	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
Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses Accumulated In Investments	-10	0
Municipal Securities, Revenue [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months, Fair Value	0	27,789
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	42	0
12 Months or More, Fair Value	3,413	0
Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses Accumulated In Investments	0	-292
Asset Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months, Fair Value	0	37,689
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
Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses Accumulated In Investments	0	-333
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less Than 12 Months, Fair Value	9,969	33,891
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments	66	0
12 Months or More, Fair Value	15,706	0
Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses Accumulated In Investments	($3)	($83)

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 $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
One year or less, Amortized Cost	$126,496	$101,537
One year through five years, Amortized Cost	855,731	609,755
Five years through ten years, Amortized Cost	118,210	157,003
Greater than ten years, Amortized Cost	20,127	29,900
Total, Amortized Cost	1,120,564	898,195
One year or less, Fair Value	127,348	102,126
One year through five years, Fair Value	859,409	610,589
Five years through ten years, Fair Value	116,873	151,221
Greater than ten years, Fair Value	20,683	30,090
Total, Fair Value	1,124,313	894,026
Restricted Deposits [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
One year or less, Amortized Cost	60,665	40,633
One year through five years, Amortized Cost	17,770	6,301
Five years through ten years, Amortized Cost	0	0
Greater than ten years, Amortized Cost	0	0
Total, Amortized Cost	78,435	46,934
One year or less, Fair Value	60,665	40,637
One year through five years, Fair Value	17,777	6,309
Five years through ten years, Fair Value	0	0
Greater than ten years, Fair Value	0	0
Total, Fair Value	$78,442	$46,946

Fair_Value_Measurements_Fair_V

Fair Value Measurements (Fair Value Measurements By Level For Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and Cash Equivalents	$1,199,784	$974,304
U.S. Treasury securities and obligations of U.S. government corporations and agencies	307,735	224,423
Corporate securities	399,348	296,086
Municipal securities, General obligation	39,408	54,422
Municipal securities, Pre-refunded	8,535	10,917
Municipal securities, Revenue	69,400	69,054
Municipal securities, Variable rate demand notes	18,000	28,575
Asset backed securities	179,985	139,050
Mortgage backed securities	48,270	33,891
Total investments	1,070,681	856,418
Cash and cash equivalents	57,608	26,642
Certificates of deposit	5,892	5,891
U.S. Treasury securities and obligations of U.S. government corporations and agencies	14,942	14,413
Total restricted deposits	78,442	46,946
Other long-term assets: Interest rate swap agreements	9,506	9,576
Total assets at fair value	2,358,413	1,887,244
Level I [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and Cash Equivalents	1,199,784	974,304
U.S. Treasury securities and obligations of U.S. government corporations and agencies	288,546	212,185
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	0	0
Total investments	288,546	212,185
Cash and cash equivalents	57,608	26,642
Certificates of deposit	5,892	5,891
U.S. Treasury securities and obligations of U.S. government corporations and agencies	14,942	14,413
Total restricted deposits	78,442	46,946
Other long-term assets: Interest rate swap agreements	0	0
Total assets at fair value	1,566,772	1,233,435
Level II [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and Cash Equivalents	0	0
U.S. Treasury securities and obligations of U.S. government corporations and agencies	19,189	12,238
Corporate securities	399,348	296,086
Municipal securities, General obligation	39,408	54,422
Municipal securities, Pre-refunded	8,535	10,917
Municipal securities, Revenue	69,400	69,054
Municipal securities, Variable rate demand notes	18,000	28,575
Asset backed securities	179,985	139,050
Mortgage backed securities	48,270	33,891
Total investments	782,135	644,233
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
Other long-term assets: Interest rate swap agreements	9,506	9,576
Total assets at fair value	791,641	653,809
Level III [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
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	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
Other long-term assets: Interest rate swap agreements	0	0
Total assets at fair value	$0	$0

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Disclosures [Abstract]	'	'
Transfers from Level I to Level II	$14,161	'
Transfers from Level II to Level I	1,214	'
Life insurance contracts and other non-majority owned investments, fair value	$53,632	$37,608

Debt_Narrative_Details

Debt (Narrative) (Details) (USD $)	3 Months Ended						1 Months Ended			1 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Apr. 30, 2014	Dec. 31, 2013	31-May-13	Apr. 30, 2013	31-May-11	31-May-11	Jun. 30, 2014	Nov. 30, 2012	Apr. 30, 2014	Jun. 30, 2014
							5.75% Senior Notes [Member]	5.75% Senior Notes [Member]	5.75% Senior Notes [Member]	4.75% Percent Senior Notes [Member] [Member]	4.75% Percent Senior Notes [Member] [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Senior notes, at par	$725,000	'	$425,000	'	'	'	$250,000	'	$175,000	$300,000	'
Fair value of interest rate swap agreements	9,506	'	9,576	'	'	'	'	8,935	'	'	571
Debt Instrument, Interest Rate, Stated Percentage	'	'	'	'	'	'	5.75%	'	'	4.75%	'
Senior notes due date	'	'	'	'	'	'	1-Jun-17	'	'	15-May-22	'
Senior notes, effective yield	'	'	'	'	'	'	6.00%	'	4.29%	'	'
Derivative, Notional Amount	'	300,000	'	'	'	250,000	'	'	'	'	'
Debt Instrument, Unamortized Premium	5,166	'	6,052	'	'	'	'	'	'	'	'
Variable rate of swap, percentage	3.73%	'	'	'	'	'	'	'	'	2.52%	'
Revolving credit facility, maximum borrowing capacity	'	'	'	500,000	350,000	'	'	'	'	'	'
Revolving credit agreement	70,000	'	150,000	'	'	'	'	'	'	'	'
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 to not exceed a maximum debt-to-EBITDA ratio of 3.0 to 1.0.	'	'	'	'	'	'	'	'	'	'
Revolving credit facility, due date	1-Jun-18	'	'	'	'	'	'	'	'	'	'
Line of Credit, Minimum carrying amount of unrestricted cash	100,000	'	'	'	'	'	'	'	'	'	'
Debt, Weighted Average Interest Rate	2.50%	'	'	'	'	'	'	'	'	'	'
Letters of Credit Outstanding, Amount	30,649	'	'	'	'	'	'	'	'	'	'
Letters of credit bore interest	0.46%	'	'	'	'	'	'	'	'	'	'
Guarantor Obligations, Maximum Exposure, Undiscounted	$159,728	'	'	'	'	'	'	'	'	'	'

Debt_Schedule_Of_Debt_Details

Debt (Schedule Of Debt) (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'	'
Senior notes, at par	$725,000	$425,000
Debt Instrument, Unamortized Premium	5,166	6,052
Interest rate swap fair value	9,506	9,576
Senior notes	739,672	440,628
Revolving credit agreement	70,000	150,000
Mortgage notes payable	71,437	72,785
Capital leases and other	9,916	5,349
Total debt	891,025	668,762
Less current portion	-6,135	-3,065
Long-term debt	$884,890	$665,697

Interest_Rate_Swap_Details

Interest Rate Swap (Details) (USD $)	1 Months Ended				1 Months Ended			1 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	31-May-11	Jun. 30, 2014	Dec. 31, 2013	31-May-11	Jun. 30, 2014	Nov. 30, 2012	Apr. 30, 2014	Jun. 30, 2014
					5.75% Senior Notes [Member]	5.75% Senior Notes [Member]	5.75% Senior Notes [Member]	4.75% Percent Senior Notes [Member] [Member]	4.75% Percent Senior Notes [Member] [Member]
Derivative [Line Items]	'	'	'	'	'	'	'	'	'
Derivative, Notional Amount	$300,000	$250,000	'	'	'	'	'	'	'
Debt Instrument, Maturity Date	'	'	'	'	1-Jun-17	'	'	15-May-22	'
Derivative, Fixed Interest Rate	4.75%	5.75%	'	'	'	'	'	'	'
Derivative, Description of Variable Rate Basis	'three month LIBOR plus 2.27%	'three month LIBOR plus 3.50%	'	'	'	'	'	'	'
Senior notes, at par	'	'	725,000	425,000	250,000	'	175,000	300,000	'
Variable rate of swap, percentage	'	'	3.73%	'	'	'	'	2.52%	'
Fair value of interest rate swap agreements	'	'	$9,506	$9,576	'	$8,935	'	'	$571

Stockholders_Equity_Details

Stockholders' Equity (Details)	6 Months Ended
	Jun. 30, 2014	Jan. 31, 2014
Stockholders' Equity Attributable to Parent [Abstract]	'	'
Percentage of acquisition	'	68.00%
Common stock issued for acquisition (in shares)	2,243,217	'

Earnings_Loss_Per_Share_Detail

Earnings (Loss) Per Share (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net earnings (loss) attributable to Centene Corporation	$47,183	$40,289	$80,999	$62,928
Discontinued operations, net of income tax expense (benefit)	1,680	-805	847	-442
Net Income (Loss) Attributable to Parent	$48,863	$39,484	$81,846	$62,486
Weighted average number of common shares outstanding (in shares)	57,758,683	54,529,036	57,622,039	53,449,077
Common stock equivalents (as determined by applying the treasury stock method)	1,958,575	2,072,624	1,925,381	1,999,319
Weighted average number of common shares and potential dilutive common shares outstanding (in shares)	59,717,258	56,601,660	59,547,420	55,448,396
Income (Loss) from Continuing Operations, Per Basic Share	$0.82	$0.74	$1.41	$1.18
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	$0.03	($0.02)	$0.01	($0.01)
Basic earnings (loss) per common share (in dollars per share)	$0.85	$0.72	$1.42	$1.17
Continuing operations, Diluted	$0.79	$0.71	$1.36	$1.14
Discontinued operations, Diluted	$0.03	($0.01)	$0.01	($0.01)
Diluted earnings (loss) per common share (in dollars per share)	$0.82	$0.70	$1.37	$1.13
Anti-dilutive stock options, restricted stock and restricted stock units excluded from the calculation of diluted earnings per common share	51,855	35,094	55,544	68,809

Segment_Information_Details

Segment Information (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
			segments	segments
Number of Reportable Segments	'	'	2	2
Revenues	$4,023,700	$2,610,539	$7,483,588	$5,136,021
Premium and service revenues	3,741,087	2,518,911	7,093,148	4,940,744
Earnings (loss) from operations	92,672	68,737	162,706	108,337
Intersegment Eliminations [Member]	'	'	'	'
Premium and service revenues	-689,614	-533,446	-1,341,355	-1,070,952
Earnings (loss) from operations	0	0	0	0
Operating Segments [Member] | Medicaid Managed Care [Member]	'	'	'	'
Premium and service revenues	3,238,638	2,335,042	6,221,184	4,641,544
Earnings (loss) from operations	63,821	45,601	107,951	54,860
Operating Segments [Member] | Specialty Services [Member]	'	'	'	'
Premium and service revenues	1,192,063	717,315	2,213,319	1,370,152
Earnings (loss) from operations	28,851	23,136	54,755	53,477
Internal Customer [Member]	'	'	'	'
Revenues	0	0	0	0
Internal Customer [Member] | Intersegment Eliminations [Member]	'	'	'	'
Revenues	-689,614	-533,446	-1,341,355	-1,070,952
Internal Customer [Member] | Operating Segments [Member] | Medicaid Managed Care [Member]	'	'	'	'
Revenues	13,789	10,292	26,614	20,345
Internal Customer [Member] | Operating Segments [Member] | Specialty Services [Member]	'	'	'	'
Revenues	675,825	523,154	1,314,741	1,050,607
External Customer [Member]	'	'	'	'
Revenues	3,741,087	2,518,911	7,093,148	4,940,744
External Customer [Member] | Intersegment Eliminations [Member]	'	'	'	'
Revenues	0	0	0	0
External Customer [Member] | Operating Segments [Member] | Medicaid Managed Care [Member]	'	'	'	'
Revenues	3,224,849	2,324,750	6,194,570	4,621,199
External Customer [Member] | Operating Segments [Member] | Specialty Services [Member]	'	'	'	'
Revenues	$516,238	$194,161	$898,578	$319,545

Contingencies_Details

Contingencies (Details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Kentucky Spirit Performance Bond	$25,000
Commonwealth of Kentucky Alleged Increased Program Costs - Low End of Range	28,000
Commonwealth of Kentucky Alleged Increased Program Costs - High End of Range	40,000
Commonwealth of Kentucky Alleged Associated CMS Expenditures - Low End of Range	92,000
Commonwealth of Kentucky Alleged Associated CMS Expenditures - High End of Range	$134,000
Loss Contingency, Allegations	'In October 2012, the Company notified the Cabinet that it was exercising a contractual right that it believes allows the Company to terminate its Medicaid managed care contract with the Commonwealth effective July 5, 2013.B 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.B In April 2013, the Commonwealth answered that lawsuit and filed counterclaims against the Company seeking declaratory relief and damages.B In May 2013, the Franklin Circuit Court ruled that Kentucky Spirit does not have a contractual right to terminate the contract early.B 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.B 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.B The Commonwealth has alleged that Kentucky Spirit's exit constitutes a material breach of contract.B The Commonwealth seeks to recover substantial damages and to enforce its rights under Kentucky Spirit's $25,000 performance bond. In March 2014, Kentucky Spirit received a demand letter from the Commonwealth seeking damages to reimburse the Commonwealth for its alleged incurred and expected losses, expenses, transition costs and other damages for the period July 6, 2013 until July 5, 2014. The letter stated that the Commonwealth is seeking damages only on behalf of the Commonwealth, not the federal Centers for Medicare and Medicaid Services (CMS). In June 2014, the Commonwealth informed the Kentucky Department of Insurance that its expenditures due to Kentucky's Spirit's departure range from $28,000 to $40,000 plus interest, and that the associated CMS expenditures range from $92,000 to $134,000. Kentucky Spirit disputes the Commonwealth's alleged damages, is pursuing its own 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.B If the Company prevails on its claims, Kentucky Spirit would be entitled to damages under its lawsuit.B If the Commonwealth prevails, a liability to the Commonwealth could be recorded.B The Company is unable to estimate the ultimate outcome resulting from the Kentucky litigation.B As a result, the Company has not recorded any receivable or any liability for potential damages under the contract as of June 30, 2014.B 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.

Subsequent_Events_Details

Subsequent Events (Details)	1 Months Ended		1 Months Ended		1 Months Ended
In Thousands, except Share data, unless otherwise specified	Jan. 31, 2014	Jun. 30, 2014	Jul. 31, 2014	Jul. 31, 2014	Jul. 31, 2014
	USD ($)	USD ($)	Ribera Salud [Member]	Ribera Salud [Member]	Community Health Solutions [Member]
			Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
			USD ($)	EUR (€)	USD ($)
Subsequent Event [Line Items]	'	'	'	'	'
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low	'	'	'	'	$110,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	'	'	'	'	140,000
Business Combination, Consideration Transferred	213,664	'	'	'	72,100
Payments to Acquire Businesses, Gross	80,978	'	'	'	14,100
Common stock issued for acquisition	132,686	'	'	'	58,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	'	'	'	'	746,369
Payments to Acquire Interest in Joint Venture	'	'	16,000	'	'
Equity Method Investment, Ownership Percentage	'	'	50.00%	'	'
Letters of Credit Outstanding, Amount	'	$30,649	$65,000	€ 48,000	'