Consolidated Statements Of Operations And Comprehensive Loss - USD ($) $ in Thousands		1 Months Ended		3 Months Ended						12 Months Ended
		Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues:
Net patient service revenue				$ 236,581	$ 243,149	$ 212,796	$ 175,108	$ 174,672	$ 169,912	$ 938,488	[1]	$ 707,616	[1]	$ 683,781	[1]
Management fees				16,762	16,856	16,597				67,012	[1]	11,139	[1]		[1]
Other revenue				2,676	3,233	2,945	2,614	2,480	2,194	12,682	[1]	10,168	[1]	9,299	[1]
Total revenues				256,019	263,238	232,338	177,722	177,152	172,106	1,018,182	[1]	728,923	[1]	693,080	[1]
Expenses:
Salaries and benefits				134,599	135,803	125,909	98,032	99,687	96,253	545,025	[1]	409,352	[1]	372,656	[1]
Medical supplies				24,771	24,502	21,734	15,917	14,407	15,842	97,367	[1]	64,640	[1]	61,589	[1]
Facility rent expenses				14,867	17,167	15,495	11,427	10,675	10,183	63,111	[1]	45,565	[1]	39,802	[1]
Other operating expenses				15,558	16,096	14,381	11,882	10,997	10,276	61,784	[1]	45,629	[1]	38,988	[1]
General and administrative expenses				37,919	34,160	30,190	25,206	23,348	20,918	135,819	[1]	107,395	[1]	83,314	[1]
Depreciation and amortization				22,358	22,134	20,694	16,032	15,297	15,150	86,583	[1]	65,096	[1]	64,814	[1]
Provision for doubtful accounts				5,621	3,428	4,296	3,767	2,015	3,075	19,253	[1]	12,146	[1]	16,916	[1]
Interest expense, net				30,233	29,899	27,527	21,952	20,473	19,944	113,279	[1]	86,747	[1]	77,494	[1]
Electronic health records incentive income	[1]									(93)
Impairment loss				47,526	182,000					229,526	[1]		[1]	81,021	[1]
Early extinguishment of debt				8,558						8,558	[1]		[1]	4,473	[1]
Loss on sale leaseback transaction		$ 100	$ 300			135				135	[1]	313	[1]		[1]
Fair value adjustment of earn-out liability				209	204	199				1,627	[1]	130	[1]	1,219	[1]
Fair value adjustment of embedded derivative	[1]									837
Gain on the sale of an interest in a joint venture								(1,460)			[1]	(1,460)	[1]		[1]
Loss on the sale / disposal of property and equipment				197	44	15	136	10	66	119	[1]	336	[1]	748	[1]
Loss on foreign currency transactions				224	62	8	315	704	9	678	[1]	1,138	[1]	241	[1]
(Gain) loss on foreign currency derivative contracts						(4)	67	190	52	(4)	[1]	467	[1]	1,165	[1]
Total expenses				342,640	470,404	260,579	204,733	196,343	191,768	1,368,509	[1]	837,494	[1]	844,440	[1]
Loss before income taxes and equity in net loss of joint ventures				(86,621)	(207,166)	(28,241)	(27,011)	(19,191)	(19,662)	(350,327)	[1]	(108,571)	[1]	(151,360)	[1]
Income tax expense (benefit)				528	95	1,618	438	773	1,250	2,319	[1]	(23,068)	[1]	3,477	[1]
Loss before equity in net loss of joint ventures				(87,149)	(207,261)	(29,859)	(27,449)	(19,964)	(20,912)	(352,646)	[1]	(85,503)	[1]	(154,837)	[1]
Equity in net loss of joint ventures				(26)	(97)	(38)	(93)	(208)	(124)	(50)	[1]	(454)	[1]	(817)	[1]
Net loss				(87,175)	(207,358)	(29,897)	(27,542)	(20,172)	(21,036)	(352,696)	[1]	(85,957)	[1]	(155,654)	[1]
Net income attributable to noncontrolling interests - redeemable and non-redeemable				(708)	(2,880)	(932)	(296)	(662)	(313)	(4,595)	[1]	(1,838)	[1]	(3,053)	[1]
Net loss attributable to 21st Century Oncology Holdings, Inc. shareholder				(87,883)	(210,238)	(30,829)	(27,838)	(20,834)	(21,349)	(357,291)	[1]	(87,795)	[1]	(158,707)	[1]
Other comprehensive loss:
Net periodic benefit cost of pension plan	[1]									(91)
Unrealized loss on derivative interest rate swap agreements, net of tax	[1]													(333)
Unrealized loss on foreign currency translation				(1,853)	(831)	(8,862)	(4,210)	(3,676)	(2,620)	(12,098)	[1]	(15,813)	[1]	(8,011)	[1]
Other comprehensive loss				(1,853)	(831)	(8,862)	(4,210)	(3,676)	(2,620)	(12,189)	[1]	(15,813)	[1]	(8,344)	[1]
Comprehensive loss:				(89,028)	(208,189)	(38,759)	(31,752)	(23,848)	(23,656)	(364,885)	[1]	(101,770)	[1]	(163,998)	[1]
Comprehensive income attributable to noncontrolling interests-redeemable and non-redeemable:				(439)	(2,757)	(87)	127	(132)	8	(3,224)	[1]	(303)	[1]	(2,216)	[1]
Comprehensive loss attributable to 21st Century Oncology Holdings, Inc. shareholder				$ (89,467)	$ (210,946)	$ (38,846)	$ (31,625)	$ (23,980)	$ (23,648)	$ (368,109)	[1]	$ (102,073)	[1]	$ (166,214)	[1]

[1] As Restated