American Renal Associates 10-K 5 Sep 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Sep. 03, 2019	Jun. 30, 2018
Document and Entity Information
Entity Registrant Name	American Renal Associates Holdings, Inc.
Entity Central Index Key	0001498068
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	No
Entity Emerging Growth Company	true
Entity Small Business	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 203,994,696
Entity Common Stock, Shares Outstanding		32,564,398
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Assets
Cash	$ 55,200	$ 61,862	$ 69,393	$ 64,273	$ 71,511	$ 67,583	$ 74,922	$ 83,993	$ 100,905	$ 105,138	$ 93,262	$ 95,961
Accounts receivable, less allowance for doubtful accounts of $3,270, $8,676, and $9,733 at December 31, 2018, 2017, and 2016, respectively	99,526	98,678	104,890	110,331	112,642	121,260	117,660	125,849	130,211	130,518	130,985	119,323
Inventories	11,433	6,382	6,535	6,129	4,665	4,672	4,960	4,648	4,676	4,468	4,790	5,515
Prepaid expenses and other current assets	28,127	18,716	19,087	25,277	24,998	17,133	23,150	18,217	18,498	12,914	14,902	19,395
Current assets held for sale	577				0				0
Total current assets	194,863	185,638	199,905	206,010	213,816	210,648	220,692	232,707	254,290	253,038	243,939	240,194
Property and equipment, net of accumulated depreciation	180,268	168,346	167,621	168,682	168,537	166,890	165,495	167,338	170,118	165,132	160,887	151,204
Deferred tax assets	0	4,596	4,596		0	9,635	9,635	9,691	10,349
Intangible assets, net of accumulated amortization	24,628	24,811	24,966	25,182	25,368	25,488	25,638	25,681	25,626	25,943	25,938	25,877
Other long-term assets	14,745	18,198	19,639	15,013	9,285	8,636	8,885	7,472	6,753	6,593	6,174	6,574
Goodwill	571,339	571,339	571,339	571,341	573,145	572,420	572,800	573,092	573,092	573,052	569,876	569,261	$ 569,264
Total assets	985,843	972,928	988,066	986,228	990,151	993,717	1,003,145	1,015,981	1,040,228	1,023,758	1,006,814	993,110
Liabilities and Equity
Accounts payable	59,082	54,023	52,849	40,885	33,421	33,863	28,184	24,605	31,127	23,277	23,515	23,857
Accrued compensation and benefits	34,587	34,658	30,881	27,160	28,985	31,767	28,654	26,092	29,103	29,092	25,469	21,496
Accrued expenses and other current liabilities	61,116	56,538	62,950	63,790	64,575	57,199	70,695	58,559	63,022	59,388	56,818	45,210
Current portion of long-term debt	42,855	47,206	46,660	45,121	44,534	44,189	45,711	45,559	48,274	43,582	40,579	27,171
Total current liabilities	197,640	192,425	193,340	176,956	171,515	167,018	173,244	154,815	171,526	155,339	146,381	117,734
Long-term debt, less current portion	517,511	506,750	509,983	512,822	515,554	514,846	516,442	520,364	522,058	520,017	517,798	661,369
Income tax receivable agreement payable	3,700	9,476	6,037	8,646	7,500	11,900	15,600	16,683	21,200	15,670	27,800
Other long-term liabilities	24,813	24,375	33,816	14,147	14,880	15,713	13,856	12,823	11,670	11,262	10,355	9,927
Deferred tax liabilities	3,169	0	0	422	422	0	0	0	0	7,954	7,954	7,954
Total liabilities	746,833	733,026	743,176	712,993	709,871	709,477	719,142	704,685	726,454	710,242	710,288	796,984
Commitments and contingencies (Notes 21 and 22)
Noncontrolling interests subject to put provisions	129,099	141,236	140,737	139,791	130,438	133,716	132,494	158,086	150,049	151,916	151,624	124,972
Equity:
Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued	0	0	0	0	0	0	0	0	0	0	0	0
Common stock, $0.01 par value; 300,000,000 shares authorized; 32,603,846, 32,034,439, and 30,894,962 issued and outstanding at December 31, 2018, December 31, 2017, and December 31, 2016, respectively	196	195	195	195	193	186	185	184	184	184	184	98
Additional paid-in capital	105,715	93,217	93,339	98,243	99,098	95,359	101,375	93,960	100,687	84,165	81,849	6,853
Receivable from noncontrolling interests	(506)	(1,340)	(477)	(515)	(358)	(484)	(415)	(747)	(544)	(562)	(498)	(605)
Accumulated deficit	(164,451)	(163,878)	(163,145)	(139,486)	(135,898)	(131,200)	(138,588)	(133,423)	(131,301)	(122,226)	(134,999)	(127,940)
Accumulated other comprehensive income (loss), net of tax	76	1,440	1,013	546	(891)	(1,447)	(1,420)	(744)	(100)	(201)	(301)	(401)
Total American Renal Associates Holdings, Inc. deficit	(58,970)	(70,366)	(69,075)	(41,017)	(37,856)	(37,586)	(38,863)	(40,770)	(31,074)	(38,640)	(53,765)	(121,995)	$ (123,211)
Noncontrolling interests not subject to put provisions	168,881	169,032	173,228	174,461	187,698	188,110	190,372	193,980	194,799	200,240	198,667	193,149
Total equity	109,911	98,666	104,153	133,444	149,842	150,524	151,509	153,210	163,725	161,600	144,902	71,154
Total liabilities and equity	$ 985,843	$ 972,928	$ 988,066	$ 986,228	$ 990,151	$ 993,717	$ 1,003,145	$ 1,015,981	$ 1,040,228	$ 1,023,758	$ 1,006,814	$ 993,110

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts receivables, allowance for doubtful accounts	$ 3,270	$ 8,676	$ 9,733
Preferred stock, par value (in USD per share)	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000	1,000,000
Preferred stock, issued (in shares)	0	0	0
Common stock, par value (in USD per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000	300,000,000
Common stock, shares issued (in shares)	32,603,846	32,034,439	30,894,962
Common stock, shares outstanding (in shares)	32,603,846	32,034,439	30,894,962

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Patient service operating revenues	$ 805,776
Patient service operating revenues		$ 737,318	$ 772,221
Provision for uncollectible accounts		(8,316)	(5,441)
Net patient service operating revenues		729,002	766,780
Operating expenses:
Patient care costs	570,009	483,101	452,453
General and administrative	101,101	102,093	127,921
Transaction-related costs	856	717	2,239
Gain on business interruption insurance	(375)	0	0
Depreciation and amortization	39,802	37,634	33,862
Certain legal and other matters	39,061	15,249	6,779
Total operating expenses	750,454	638,794	623,254
Operating income	55,322	90,208	143,526
Interest expense, net	(32,632)	(29,309)	(35,959)
Loss on early extinguishment of debt	0	(526)	(4,708)
Change in fair value of income tax receivable agreement	2,673	7,234	1,286
Income before income taxes	25,363	67,607	104,145
Income tax expense	2,896	9,471	2,479
Net income (loss)	22,467	58,136	101,666
Less: Net income attributable to noncontrolling interests	(51,234)	(62,733)	(98,520)
Net (loss) income attributable to American Renal Associates Holdings, Inc.	(28,767)	(4,597)	3,146
Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests	(2,566)	(11,503)	(10,067)
Net income (loss) attributable to common shareholders	$ (31,333)	$ (16,100)	$ (6,921)
Loss per share:
Basic (in USD per share)	$ (0.98)	$ (0.52)	$ (0.25)
Diluted (in USD per share)	$ (0.98)	$ (0.52)	$ (0.25)
Weighted-average number of common shares outstanding
Basic (in shares)	31,965,844	31,081,824	28,118,673
Diluted (in shares)	31,965,844	31,081,824	28,118,673
Cash dividends declared per share (in USD per share)	$ 0	$ 0	$ 1.30

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Thousands	3 Months Ended									6 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 12,512	$ (8,383)	$ 7,164	$ 25,791	$ 9,759	$ 11,762	$ 36,117	$ 21,169	$ 31,990	$ (1,219)	$ 21,521	$ 53,159	$ 11,293	$ 47,312	$ 89,276	$ 22,467	$ 58,136	$ 101,666
Unrealized gain (loss) on derivative agreements, net of tax	427	467	1,651	(27)	(676)	(644)	100	100	100	2,118	(1,320)	200	2,545	(1,347)	300	1,181	(791)	401
Total comprehensive income	12,939	(7,916)	8,815	25,764	9,083	11,118	36,217	21,269	32,090	899	20,201	53,359	13,838	45,965	89,576	23,648	57,345	102,067
Less: Comprehensive income attributable to noncontrolling interests	(13,246)	(15,276)	(10,966)	(18,295)	(14,832)	(13,884)	(23,345)	(28,242)	(25,469)	(26,242)	(28,716)	(53,711)	(39,488)	(47,011)	(77,056)	(51,234)	(62,733)	(98,520)
Total comprehensive (loss) income attributable to American Renal Associates Holdings, Inc.	$ (307)	$ (23,192)	$ (2,151)	$ 7,469	$ (5,749)	$ (2,766)	$ 12,872	$ (6,973)	$ 6,621	$ (25,343)	$ (8,515)	$ (352)	$ (25,650)	$ (1,046)	$ 12,520	$ (27,586)	$ (5,388)	$ 3,547

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Noncontrolling Interests subject to put provisions	Common Stock	Additional Paid-in Capital	Receivable from Noncontrolling Interest Holders	Retained Earnings (Deficit)	Accumulated Other Comprehensive Income (loss)	Noncontrolling Interests not subject to put provisions
Balance at beginning of period at Dec. 31, 2015	$ (123,211)	$ 117,575	$ 98	$ 0	$ (529)	$ (122,279)	$ (501)	$ 188,843
Balance at beginning of period (in shares) at Dec. 31, 2015			22,213,967
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	6,521
Change in fair value of interest rate swaps, net of tax	100
Balance at end of period at Mar. 31, 2016	(121,995)
Balance at beginning of period at Dec. 31, 2015	(123,211)	117,575	$ 98	0	(529)	(122,279)	(501)	188,843
Balance at beginning of period (in shares) at Dec. 31, 2015			22,213,967
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(552)
Change in fair value of interest rate swaps, net of tax	200
Balance at end of period at Jun. 30, 2016	(53,765)
Balance at beginning of period at Dec. 31, 2015	(123,211)	117,575	$ 98	0	(529)	(122,279)	(501)	188,843
Balance at beginning of period (in shares) at Dec. 31, 2015			22,213,967
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	12,220
Change in fair value of interest rate swaps, net of tax	300
Balance at end of period at Sep. 30, 2016	(38,640)
Balance at beginning of period at Dec. 31, 2015	(123,211)	117,575	$ 98	0	(529)	(122,279)	(501)	188,843
Balance at beginning of period (in shares) at Dec. 31, 2015			22,213,967
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	3,146	28,162				3,146		70,358
Stock‑based compensation	40,285			40,285
Exercise of stock option (in shares)			55,995
Exercise of stock options	(186)			(186)
Number of shares sold in public offering (in shares)			8,625,000
Issuance of common stock sold in initial public offering, net of offering expense	170,131		$ 86	170,045
Cash dividends, $1.30 per common share	(28,886)			(28,886)
Cash dividend equivalents paid on share-based payments	(1,355)			(1,355)
Cash dividend equivalents accrued on share-based payments	(6,688)			(6,688)
Non-cash dividends	(26,233)			(26,233)
Income tax receivable agreement dividend	(23,400)			(23,400)
Distributions to noncontrolling interests		(27,048)						(67,419)
Contributions from noncontrolling interests	(15)	3,249			(15)			4,236
Purchases of noncontrolling interests	(7,680)			(7,680)				(717)
Sales of noncontrolling interests	99	127		99				0
Reclassification and other adjustments		502						(502)
Change in fair value of interest rate swaps, net of tax	401						401
Change in fair value of noncontrolling interests	(27,482)	27,482		(15,314)		(12,168)
Balance at end of period at Dec. 31, 2016	(31,074)	150,049	$ 184	100,687	(544)	(131,301)	(100)	194,799
Balance at end of period (in shares) at Dec. 31, 2016			30,894,962
Balance at beginning of period at Mar. 31, 2016	(121,995)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(7,073)
Change in fair value of interest rate swaps, net of tax	100
Balance at end of period at Jun. 30, 2016	(53,765)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	12,772
Change in fair value of interest rate swaps, net of tax	100
Balance at end of period at Sep. 30, 2016	(38,640)
Balance at beginning of period at Dec. 31, 2016	(31,074)	150,049	$ 184	100,687	(544)	(131,301)	(100)	194,799
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(2,122)
Change in fair value of interest rate swaps, net of tax	(644)
Balance at end of period at Mar. 31, 2017	(40,770)
Balance at beginning of period at Dec. 31, 2016	(31,074)	150,049	$ 184	100,687	(544)	(131,301)	(100)	194,799
Balance at beginning of period (in shares) at Dec. 31, 2016			30,894,962
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(7,195)
Change in fair value of interest rate swaps, net of tax	(1,320)
Balance at end of period at Jun. 30, 2017	(38,863)
Balance at beginning of period at Dec. 31, 2016	(31,074)	150,049	$ 184	100,687	(544)	(131,301)	(100)	194,799
Balance at beginning of period (in shares) at Dec. 31, 2016			30,894,962
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	301
Change in fair value of interest rate swaps, net of tax	(1,347)
Balance at end of period at Sep. 30, 2017	(37,586)
Balance at beginning of period at Dec. 31, 2016	(31,074)	150,049	$ 184	100,687	(544)	(131,301)	(100)	194,799
Balance at beginning of period (in shares) at Dec. 31, 2016			30,894,962
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(4,597)	17,224				(4,597)		45,509
Stock‑based compensation	15,872			15,872
Exercise of stock option (in shares)			861,866
Exercise of stock options	2,380		$ 9	2,371
Cash dividend equivalents accrued on share-based payments	(2,880)			(2,880)
Issuance of Restricted Stock (In shares)			277,611
Issuance of Restricted Stock	0
Distributions to noncontrolling interests		(23,656)						(55,822)
Contributions from noncontrolling interests	186	3,015			186			3,321
Purchases of noncontrolling interests	(7,566)	(25,317)		(7,566)				(353)
Sales of noncontrolling interests	231	32		231				(282)
Reclassification and other adjustments		(526)						526
Change in fair value of interest rate swaps, net of tax	(791)						(791)
Change in fair value of noncontrolling interests	(9,617)	9,617		(9,617)
Balance at end of period at Dec. 31, 2017	(37,856)	130,438	$ 193	99,098	(358)	(135,898)	(891)	187,698
Balance at end of period (in shares) at Dec. 31, 2017			32,034,439
Balance at beginning of period at Mar. 31, 2017	(40,770)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(5,073)
Change in fair value of interest rate swaps, net of tax	(676)
Balance at end of period at Jun. 30, 2017	(38,863)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	7,496
Change in fair value of interest rate swaps, net of tax	(27)
Balance at end of period at Sep. 30, 2017	(37,586)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(4,898)
Balance at end of period at Dec. 31, 2017	(37,856)	130,438	$ 193	99,098	(358)	(135,898)	(891)	187,698
Balance at end of period (in shares) at Dec. 31, 2017			32,034,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(3,802)
Change in fair value of interest rate swaps, net of tax	1,651
Balance at end of period at Mar. 31, 2018	(41,017)
Balance at beginning of period at Dec. 31, 2017	(37,856)	130,438	$ 193	99,098	(358)	(135,898)	(891)	187,698
Balance at beginning of period (in shares) at Dec. 31, 2017			32,034,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(27,461)
Change in fair value of interest rate swaps, net of tax	2,118
Balance at end of period at Jun. 30, 2018	(69,075)
Balance at beginning of period at Dec. 31, 2017	(37,856)	130,438	$ 193	99,098	(358)	(135,898)	(891)	187,698
Balance at beginning of period (in shares) at Dec. 31, 2017			32,034,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(28,195)
Change in fair value of interest rate swaps, net of tax	2,545
Balance at end of period at Sep. 30, 2018	(70,366)
Balance at beginning of period at Dec. 31, 2017	(37,856)	130,438	$ 193	99,098	(358)	(135,898)	(891)	187,698
Balance at beginning of period (in shares) at Dec. 31, 2017			32,034,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(28,767)	13,633				(28,767)		37,601
Reclassification of stranded tax effects related to the Tax Cuts and Jobs Act of 2017						214	(214)
Stock‑based compensation	$ 5,721			5,721
Exercise of stock option (in shares)	348,442		348,442
Exercise of stock options	$ 1,398		$ 3	1,395
Cash dividend equivalents accrued on share-based payments	478			478
Issuance of Restricted Stock (In shares)			359,691
Issuance of Restricted Stock	$ 0
Forfeiture of restricted stock options (In shares)			(70,382)
Common stock repurchases for tax withholdings of net settlement of equity awards (in shares)	(49,406)
Common stock repurchases for tax withholdings of net settlement of equity awards	$ (417)			(417)
Vested restricted stock awards withheld on net share settlement (in shares)			(18,938)
Vested restricted stock awards withheld on net share settlement	(421)			(421)
Distributions to noncontrolling interests		(20,243)						(50,717)
Contributions from noncontrolling interests	(148)	2,623			(148)			5,264
Purchases of noncontrolling interests	(6,645)	(1,062)		(6,645)				(1,359)
Sales of noncontrolling interests	(891)	166		(891)				1,335
Reclassification and other adjustments		10,941						(10,941)
Change in fair value of interest rate swaps, net of tax	1,181						1,181
Change in fair value of noncontrolling interests	7,397	(7,397)		7,397
Balance at end of period at Dec. 31, 2018	(58,970)	129,099	$ 196	105,715	(506)	(164,451)	76	168,881
Balance at end of period (in shares) at Dec. 31, 2018			32,603,846
Balance at beginning of period at Mar. 31, 2018	(41,017)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(23,659)
Change in fair value of interest rate swaps, net of tax	467
Balance at end of period at Jun. 30, 2018	(69,075)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(734)
Change in fair value of interest rate swaps, net of tax	427
Balance at end of period at Sep. 30, 2018	(70,366)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(572)
Balance at end of period at Dec. 31, 2018	$ (58,970)	$ 129,099	$ 196	$ 105,715	$ (506)	$ (164,451)	$ 76	$ 168,881
Balance at end of period (in shares) at Dec. 31, 2018			32,603,846

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / shares
Statement of Stockholders' Equity [Abstract]
Offering costs | $	$ 19,619
Cash dividends, per common share (in USD per share) | $ / shares	$ 1.30

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income	$ 22,467	$ 58,136	$ 101,666
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	39,802	37,634	33,862
Amortization of discounts, fees and deferred financing costs	1,981	2,031	2,595
Loss on early extinguishment of debt	0	526	4,708
Stock-based compensation	5,721	15,872	40,285
Premium paid for interest rate cap agreements	0	(1,186)	0
Deferred taxes	2,350	11,299	(18,570)
Change in fair value of income tax receivable agreement	(2,673)	(7,234)	(1,286)
Non-cash charge related to derivative agreements	46	173	473
Non-cash rent charges	73	1,044	2,191
Loss (gain) on disposal of assets	80	(27)	857
Change in operating assets and liabilities, net of acquisitions:
Accounts receivable	13,118	17,568	(21,221)
Inventories	(6,799)	11	(385)
Prepaid expenses and other current assets	(2,340)	(6,353)	(4,768)
Other assets	(5,712)	(1,325)	(219)
Accounts payable	25,661	2,294	8,556
Accrued compensation and benefits	5,602	(118)	6,599
Accrued expenses and other liabilities	7,027	(1,797)	16,863
Cash provided by operating activities	106,404	128,548	172,206
Investing activities
Purchases of property, equipment and intangible assets	(44,960)	(36,073)	(61,432)
Proceeds from asset sales	2,502	2,325	0
Cash paid for acquisitions	(388)	(1,555)	(4,507)
Cash used in investing activities	(42,846)	(35,303)	(65,939)
Financing activities
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense	0	0	175,254
Net proceeds from issuance of long-term debt	0	267,564	60,000
Cash paid for financing costs	0	(3,914)	(1,350)
Proceeds on term loans, net of deferred financing costs	82,389	49,921	70,590
Payments on long-term debt	(90,428)	(327,331)	(275,243)
Dividends and dividend equivalents paid	(332)	(8,729)	(30,241)
Proceeds from exercise of stock options	1,398	2,380	170
Common stock repurchases for tax withholdings of net settlement of equity awards	(417)	0	(356)
Repurchases of vested restricted stock awards withheld on net share settlement	(421)	0	0
Distributions to noncontrolling interests	(70,960)	(79,478)	(94,468)
Contributions from noncontrolling interests	7,739	6,522	7,470
Purchases of noncontrolling interests	(9,066)	(29,540)	(8,397)
Proceeds from sales of additional noncontrolling interests	229	66	227
Cash used in financing activities	(79,869)	(122,539)	(96,344)
(Decrease) increase in cash	(16,311)	(29,294)	9,923
Cash at beginning of year	71,611	100,905	90,982
Cash and restricted cash at end of year	55,300	71,611	100,905
Supplemental Disclosure of Cash Flow Information
Cash paid for income taxes	2,635	1,885	16,095
Cash paid for interest	30,504	26,812	32,499
Supplemental Disclosure of Non-Cash Flow Information
Liability accrued for initial fair value of Tax Receivable Agreement	0	0	23,400
Dividends declared not paid	0	0	26,232
Assets acquired under capital lease obligations	6,168	0	0
Change in liability accrued for dividend equivalent payments	(478)	2,880	6,688
Contributions from noncontrolling interests in the form of a receivable	148	0	15
Liability accrued for purchases of noncontrolling interests	0	3,696	0
Non-cash portion of long-term debt refinancing	$ 0	$ 167,808	$ 0

Basis of Presentation and Organ

Basis of Presentation and Organization	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Organization	Basis of Presentation and Organization Business American Renal Associates Holdings, Inc. (“the Company”) owns 100% of the membership units of its subsidiary American Renal Holdings Intermediate Company, LLC, which itself has no assets other than 100% of the shares of capital stock of American Renal Holdings Inc. All of the Company's operating activities are conducted through American Renal Holdings Inc. and its operating subsidiaries (“ARH”). The Company is a national provider of kidney dialysis services for patients suffering from chronic kidney failure, also known as end stage renal disease (“ESRD”). As of December 31, 2018 , the Company owned and operated 241 dialysis clinics treating 16,543 patients in 27 states and the District of Columbia. As of December 31, 2017 , the Company owned and operated 228 dialysis clinics treating 15,637 patients in 26 states and the District of Columbia. The Company’s operating model is based on shared ownership of its facilities with physicians, known as nephrologists, who specialize in treating kidney‑related diseases in the local market served by the clinic. Substantially all clinics are maintained as a separate joint venture (“JV”) in which the Company has a controlling interest and its local nephrologist partners have noncontrolling interests.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The Company's consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries and variable interest entities that operate its clinics (“joint ventures”). For its joint ventures, the Company has determined that a majority voting interest and/or contractual rights granted to it provides the Company with the ability to direct the activities of these entities, and therefore the Company has determined that it is the primary beneficiary of these entities. Accordingly, the financial results of these joint ventures are fully consolidated into the Company’s operating results. The equity interests of the outside investors in the equity and results of operations of these consolidated entities are accounted for and presented as noncontrolling interests. All significant intercompany balances and transactions of the Company's wholly owned subsidiaries and joint ventures, including management fees from subsidiaries, are eliminated in consolidation. Refer to “ Note 12 - Variable Interest Entities ”. Use of Estimates The preparation of financial statements in conformity with U.S GAAP requires the use of estimates and assumptions that affect the reported amounts of revenues, expenses, assets, liabilities, and contingencies. Although actual results in subsequent periods will differ from these estimates, such estimates are developed based on the best information available to management and management’s best judgments at the time made. All significant assumptions and estimates underlying the reported amounts in the consolidated financial statements and accompanying notes are regularly reviewed and updated. Changes in estimates are reflected in the financial statements based upon ongoing actual experience, trends, or subsequent settlements and realizations, depending on the nature and predictability of the estimates and contingencies. The most significant assumptions and estimates underlying these financial statements and accompanying notes involve revenue recognition and provisions for uncollectible accounts, impairments and valuation adjustments, the useful lives of property and equipment, fair value measurements, accounting for income taxes, acquisition accounting valuation estimates, commitments and contingencies and stock‑based compensation. Specific risks and contingencies related to these estimates are further addressed within the notes to the consolidated financial statements. Segment Information Accounting pronouncements establish standards for the manner in which public companies report information about operating segments in annual and interim financial statements. Operating segments are identified as components of an enterprise for which separate discrete financial information is evaluated regularly by the chief operating decision‑maker in making decisions about how to allocate resources and assess performance. Based on its operating management and financial reporting structure, the Company has determined that it is operating as one reportable business segment, the ownership and operation of dialysis clinics, all of which are located in the United States. Net Patient Service Operating Revenues and Accounts Receivable The major component of the Company's revenues is derived from dialysis treatments and related services. Sources of payment of revenues are principally from government-based programs, including Medicare, Medicaid and state workers' compensation programs, commercial insurance payors and other sources such as the U.S. Department of Veterans Affairs (the “VA”), hospitals as well as patient self-pay. Net patient service operating revenues are reported at the amounts that reflect the consideration to which the Company expects to be entitled in exchange for providing dialysis treatments and related services. Amounts may include variable consideration for discounts, price concessions and retroactive revenue adjustments due to new information obtained, such as actual payment receipt, as well as settlement of audits, reviews and investigations. Third-party payors, patients and other payors are generally billed at least monthly, typically in the month the dialysis treatment is performed, and payment is due upon receipt. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is defined as the unit of account under ASC 606, Revenue from Contracts with Customers . The Company has determined that one performance obligation exists, a single dialysis treatment, which is satisfied over time as a dialysis treatment is provided. While the Company provides patients with other related services, they are considered a bundle of interrelated services with dialysis treatment as the primary service. Revenue is measured using the output method, which is based upon the delivery of a dialysis treatment to the patient. The Company believes that this method reflects the satisfaction of the performance obligation. All performance obligations are satisfied at the end of each reporting period. The Company maintains a usual and customary fee schedule for dialysis treatment and other related services. However, the transaction price is typically recorded at a discount to the fee schedule. The transaction prices for Medicare and Medicaid programs are based on predetermined net realizable rates per treatment that are established by statutes or regulations. For Medicare programs, the Company receives 80% of the payment directly from Medicare as established under the government’s bundled payment system. The transaction prices for contracted payors are based on contracted rates. For other payors, the Company determines the transaction price based on usual and customary rates for services provided, reduced by contractual adjustments provided to third-party payors, discounts provided to uninsured patients in accordance with the Company’s policy, and/or implicit price concessions. The Company determines its estimate of implicit price concessions based on its historical collection experience with each payor, and where no prior experience exists, it considers information from the patient's health plan. Amounts billed that have not yet been collected and that meet the conditions for unconditional right to payment are presented as net accounts receivable. Contractual adjustments result from differences between the rates charged for services performed and expected reimbursements from third-party payors. Contractual adjustments and discounts with third-party payors are considered variable consideration and are included in the determination of the estimated transaction price for providing patient care. In assessing the probability of these claim payments, the Company considers previous payment history when recording a reserve, generally at the patient level, that results in an estimate of expected revenue such that it is probable that a significant revenue reversal will not occur in future periods. There are significant challenges associated with estimating revenue, with certain transactions taking several years to resolve. Estimates are subject to ongoing insurance coverage changes, geographic coverage differences, differing interpretations of contract coverage and other payor issues, as well as other issues including determining applicable primary and secondary coverage, changes in patient coverage and coordination of benefits. As these estimates are refined over time, both positive and negative adjustments to revenue are recognized in the current period. Settlements with third-party payors for retroactive adjustments due to audits, reviews or investigations are considered variable consideration and are included in the determination of the estimated transaction price for providing dialysis treatments and related services. These settlements are estimated based on the terms of the payment agreement with the payor, correspondence from the payor and the Company’s historical settlement activity, including an assessment to ensure that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty periods end and as adjustments become known (i.e., new information becomes available), or as years are settled or are no longer subject to such audits, reviews and investigations. The Company recorded $5,521 of revenue during the year ended December 31, 2018 related to adjustments arising from a change in the transaction price in instances where the performance obligation was satisfied in a previous period related to a payor. Excluding the impact of this payor, adjustments arising from a change in the transaction price in instances where the performance obligation was satisfied in a previous period, were immaterial for the year ended December 31, 2018 . These changes in transaction price are mostly attributable to an adjustment for balances with non-contracted payors. When the Company obtains new information, such as actual cash receipts, it adjusts the estimated transaction price. Amounts pending approval from third-party payors associated with Medicare recovery claims as of December 31, 2018 , 2017 , and 2016 other than standard monthly billing, consisted of approximately $ 15,820 , $ 10,744 , and $9,224 , respectively. As of December 31, 2018 , $10,622 is classified as Prepaid expenses and other current assets and $5,198 is classified as Other long-term assets. As of December 31, 2017 and 2016 , the entire balance is classified as Prepaid expense and other current assets. The composition of patient care service revenue by payment source is as follows: Year Ended December 31, 2018 2017 2016 Percentage of Revenues by Payor: (restated) (restated) Medicare and Medicare Advantage 67 % 61 % 54 % Commercial and other (1) 28 % 35 % 43 % Medicaid and Managed Medicaid 4 % 3 % 2 % Other (2) 1 % 1 % 1 % 100 % 100 % 100 % ________________________ (1) Principally commercial insurance companies and also includes the VA. (2) Other sources of payment of revenues include hospitals and patient self-pay. Patient self-pay revenues consist of payments received directly from patients who are either uninsured or self-pay a portion of the bill. Net accounts receivable from the Medicare and Medicaid programs accounted for 70.4% , 56.2% , and 42.3% of total patient net accounts receivable as of December 31, 2018 , 2017 , and 2016 , respectively. No other single payor accounted for more than 10% of total patient net accounts receivable. Contingencies The Company and its subsidiaries are defendants in various legal actions in the normal course of business and legal actions relating the restatement of previously issued consolidated financial statements as described in “Note 3 - Restatement of Consolidated Financial Statements.” The Company records a liability when it believes that it is probable that a loss has been incurred, and the amount can be reasonably estimated. If it determines that a loss is reasonably possible and the loss or range of loss can be estimated, the Company discloses the possible loss in the Notes to the Consolidated Financial Statements. The Company evaluates, on a quarterly basis, developments in its legal matters that could affect the amount of liability that has been previously accrued, and the matters and related reasonably possible losses disclosed, and make adjustments and changes to its disclosures as appropriate. Significant judgment is required to determine both likelihood of there being and the estimated amount of a loss related to such matters. Until the final resolution of such matters, there may be an exposure to loss in excess of the amount recorded, and such amounts could be material. Should any of the Company's estimates and assumptions change or prove to have been incorrect, it could have a material impact on its business, consolidated financial position, results of operations, or cash flows. See “ Note 21 - Commitments and Contingencies ” and “ Note 22 - Certain Legal and Other Matters ” for additional information. Fair Value Measurements The Company estimates the fair value of certain assets, liabilities and noncontrolling interests subject to put provisions based upon certain valuation techniques that include observable or unobservable inputs and assumptions that market participants would use in valuing these assets, liabilities and noncontrolling interests. The Company also has classified certain assets, liabilities and noncontrolling interests subject to put provisions that are measured at fair value into the appropriate fair value hierarchy levels. The determination of the fair value of these assets and liabilities is a critical accounting estimate that involves significant judgments and assumptions and may not be indicative of the actual values at which these assets could be sold to a third party or at which these obligations could be settled. For more information on the Company's noncontrolling interests, see “ — Noncontrolling interests.” Inventories Inventories are stated at the lower of cost (first‑in, first‑out method) or market, and consist principally of pharmaceuticals and dialysis‑related consumable supplies. Property and Equipment We account for property and equipment at cost less accumulated depreciation and amortization. Depreciation is being recorded over the remaining useful lives. Property and equipment acquired as part of an acquisition are recorded at fair value and other purchases are stated at cost with depreciation calculated using the straight‑line method over their estimated useful lives as follows: Buildings 39 years Leasehold improvements Shorter of lease term or useful lives Equipment and information systems 3 to 10 years Upon retirement or sale, the cost and related accumulated depreciation are removed from the accounts, and any resulting gain or loss is credited or charged to income. Maintenance and repairs are charged to expense as incurred. Included in construction in progress are amounts expended for leasehold improvement costs incurred for new dialysis clinics and clinic expansions, in each case, that are not in service as of December 31 of the applicable year. Amortizable Intangible Assets Amortizable intangible assets include noncompete agreements, certificates of need and right of first refusal waivers. Each of these assets is amortized on a straight‑line basis over the term of the agreement, which is generally 5 to 10 years. Identified Non‑Amortizable Intangible Assets and Goodwill Goodwill represents the excess cost of a business acquisition over the fair value of the net assets acquired. Indefinite‑life identifiable intangible assets consist primarily of trademarks are considered indefinite when they are expected to generate cash flows indefinitely. Goodwill and indefinite‑life identifiable intangible assets are not amortized but are tested for impairment at least annually. The Company performs its annual review in the fourth quarter of each year, or more frequently if indicators of potential impairment exist, to determine if the carrying value of the recorded goodwill or indefinite lived intangible assets is greater than the fair value, indicating impairment. If an asset is impaired, the difference between the carrying value of the asset reflected on the financial statements and its current fair value is recognized as an expense in the period in which the impairment occurs. The Company elected to early adopt Accounting Standards Update (“ASU”) 2017-04, Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment , effective as of the annual review performed in the fourth quarter of 2017. The new guidance removes the requirement to perform a hypothetical purchase price allocation to measure goodwill impairment (Step 2). Under the new guidance, a goodwill impairment is calculated as the amount by which a reporting unit’s carrying value exceeds its fair value. The Company has determined it has one reporting unit for goodwill impairment testing purposes as it aggregated its dialysis clinics due to their similar operations components and economic characteristics of the Company. Each annual reporting period, the Company can elect to initially perform a qualitative assessment to determine whether it is necessary to perform the quantitative goodwill impairment test. If the Company believes, as a result of its qualitative assessment, that it is not more likely than not that the fair value of the reporting unit is less than its carrying amount, then the quantitative goodwill impairment test is unnecessary. If the Company elects to bypass the qualitative assessment option, or if potential impairment circumstances are considered to exist, the Company will perform the quantitative goodwill impairment test. The Company performs the quantitative goodwill impairment test using a discounted cash flow analysis, comparing the fair value with the carrying amount of the reporting unit. Such analysis is based on macro-economic factors and research, current financial information such as current results of operations and balance sheets, and projected financial results, which include only anticipated growth from current operations. The weighted average cost of capital method is used to determine the discount rate and the Gordon Growth Model is used to determine the residual value necessary for the discounted cash flow method. Changes in the estimates or assumptions used in these models could impact the results of the valuations. If the carrying amount of the reporting unit exceeds its fair value, the Company would record the difference as an impairment loss as an expense in the period in which the impairment occurred. The carrying value of goodwill included on the Company's consolidated balance sheet as of the annual impairment test date of October 1, 2018 was $571,339 . The Company’s quantitative impairment test performed for goodwill in 2018 indicated that no impairment charge was necessary for the year ended December 31, 2018 . Based on similar assessments and tests performed in the years ended December 31, 2017 , and 2016 , no impairment was identified for those respective years. The impairment test for indefinite-lived intangibles other than goodwill consists of a comparison of the fair value of the indefinite-lived intangible asset to the carrying value of the asset as of the impairment testing date. The Company estimates the fair value of its indefinite-lived intangibles using a discounted cash flow model based on its best estimate of amounts and timing of future revenues and cash flows and its most recent business and strategic plans, and compares the estimated fair value to the carrying value of the asset. For its 2018 impairment assessment, which occurred as of October 1, 2018, the Company performed quantitative assessments for all indefinite‑lived intangible assets. The estimated fair values exceeded the carrying value for each of the Company’s indefinite-lived intangible assets as of the annual testing date, and therefore the Company has concluded that there was no impairment for the year ended December 31, 2018 . Based on similar assessments and tests performed in the years ended December 31, 2017 and 2016 , the Company has concluded that there was no impairment for those respective years. Impairment of Long‑Lived Assets Long‑lived assets include property and equipment and finite‑lived intangibles. In the event that facts and circumstances indicate that these assets may be impaired, an evaluation of recoverability at the lowest asset group level would be performed. If an evaluation is required, the estimated future undiscounted cash flows associated with the asset would be compared to the asset’s carrying amount to determine if a write‑down to fair value is required. The lowest level for which identifiable cash flows exist is the operating clinic level. No facts or circumstances were identified that indicated that these assets may be impaired, and as such there was no impairment charge recorded for the year ended December 31, 2018 . Based on similar assessments performed in the years ended December 31, 2017 and 2016 , no impairment charge was recorded for those respective years. Assets Held for Sale The Company classifies its long-lived assets to be sold as held for sale in the period (i) it has approved and committed to a plan to sell the asset, (ii) the asset is available for immediate sale in its present condition, (iii) an active program to locate a buyer and other actions required to sell the asset have been initiated, (iv) the sale of the asset is probable, (v) the asset is being actively marketed for sale at a price that is reasonable in relation to its current fair value and (vi) it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. The Company initially measures a long-lived asset that is classified as held for sale at the lower of its carrying value or fair value less any costs to sell. Any loss resulting from this measurement is recognized in the period in which the held for sale criteria are met. Conversely, gains are not recognized on the sale of a long-lived asset until the date of sale. Upon designation as an asset held for sale, the Company stops recording depreciation expense on the asset. The Company assesses the fair value of a long-lived asset less any costs to sell at each reporting period and until the asset is no longer classified as held for sale. As of December 31, 2018, certain clinics in Maryland met the criteria to be classified as held for sale and the Company concluded that there was no impairment for these assets. We reclassified the property and equipment, inventory, and certain other assets, which had a combined carrying value of $0.6 million , to Current assets held for sale on the consolidated balance sheet. The sale of these clinics was executed on July 1, 2019, Refer to “ Note 25 - Subsequent Events ” for further discussion related to the clinic divestitures. There were no assets that met the criteria for classification as held for sale as of December 31, 2017 or 2016 . Income Taxes The Company accounts for income taxes under the liability approach. Under this approach, deferred tax assets and liabilities are recognized based upon temporary differences between the financial statement and tax bases of assets and liabilities, as measured by the enacted tax rates, which will be in effect when these differences reverse. Deferred tax expense or benefit is the result of changes in deferred tax assets and liabilities between reporting periods. A valuation allowance is established when, based on an evaluation of objectively verifiable evidence, there is a likelihood that some portion or all of the deferred tax assets will not be realized. The Company is not taxed on the share of pre‑tax income attributable to noncontrolling interests, and net income attributable to noncontrolling interests in its consolidated financial statements has not been presented net of income taxes attributable to these noncontrolling interests. Therefore, the Company’s income tax provision (benefit) relates to its share of pre‑tax income (losses) from its ownership interest in its subsidiaries as these entities are pass‑through entities for tax purposes. The Company recognizes a tax position in its financial statements when that tax position, based upon its technical merits, is more likely than not to be sustained upon examination by the relevant taxing authority. Once the recognition threshold is met, the tax position is then measured to determine the actual amount of benefit to recognize in the financial statements. In addition, the recognition threshold of more‑likely‑than‑not must continue to be met in each reporting period to support continued recognition of the tax benefit. Tax positions that previously failed to meet the more‑likely‑than‑not recognition threshold are recognized in the first financial reporting period in which that threshold is met. Previously recognized tax positions that no longer meet the more‑likely‑than‑not recognition threshold are derecognized in the financial reporting period in which that threshold is no longer met. The Company recognizes interest and penalties related to unrecorded tax positions in its income tax expense. Noncontrolling Interests The Company owns a controlling interest in the majority of its clinics as of December 31, 2018 , and its joint venture partners own the remaining noncontrolling interests. The Company is required to treat noncontrolling interests (other than noncontrolling interests subject to put provisions) as a separate component of equity, but apart from its own equity, and not as a liability or other item outside of equity. The Company is also required to present separately consolidated net income (loss) attributable to ARA and to noncontrolling interests on the face of the consolidated statement of income. In addition, changes in the Company's ownership interest while it retains a controlling financial interest are prospectively accounted for as equity transactions. The Company is also required to expand disclosures in the financial statements to include a reconciliation of the beginning and ending balances of the equity attributable to the Company and the noncontrolling owners and a schedule showing the effects of changes in the Company's ownership interest in a subsidiary on the equity attributable to the Company. Further, the Company is also required to classify securities with redemption features that are not solely within the Company’s control, such as the Company’s noncontrolling interests that are subject to put provisions, outside of permanent equity. These noncontrolling interests subject to put provisions are recorded at the greater of the noncontrolling interest balance determined pursuant to ASC 810-10, Consolidation , or the redemption value. Changes in the fair value of noncontrolling interests subject to put provisions are accounted for as equity transactions. Changes in the redemption value over fair value are recognized as reductions of earnings available to shareholders of the Company. These put provisions, if exercised, would require the Company to purchase its nephrologist partners' interests at the appraised fair value or the redemption value as defined in the specific put provision. The Company estimates the fair value of the noncontrolling interests subject to these put provisions using the income, market and asset-based approaches. The fair value derived from the methods used is evaluated and weighted, as appropriate, considering the reasonableness of the range of values indicated. Under the income approach, fair value may be determined by utilizing a weighted average cost of capital to discount the expected cash flows to a single present value amount using current expectations about those future amounts. Under the market approach, fair value may be determined by reference to multiples of market-comparable companies or transactions, including revenue and EBITDA multiples. The estimated fair values of the interests subject to these put provisions can also fluctuate and the implicit multiples at which these obligations may be settled may vary depending upon market conditions and access to the credit and capital markets, which can impact the level of competition for dialysis and non-dialysis related businesses and the economic performance of these businesses. See “ Note 13 - Noncontrolling Interests Subject to Put Provisions ” for further details. Stock‑Based Compensation The Company measures and recognizes compensation expense for all share‑based payment awards based on estimated fair values at the date of grant. Determining the fair value of share‑based awards requires judgment in developing assumptions, which involve a number of variables. The Company estimates fair value by using a Monte Carlo simulation‑based approach for the portion of the option that contains both a market and performance condition and the Black‑Scholes valuation model for the portion of the option that contains a performance or a service‑based condition. The fair value of restricted stock awards is equal to the closing sale price of the Company’s common stock on the date of grant. Key inputs used to estimate the fair value of stock options include the exercise price of the award, the expected term of the option, the expected volatility of the common stock over the option’s expected term, the risk‑free interest rate over the option’s expected term and the Company’s expected annual dividend yield. Since the Company has limited history as a public company and does not yet have sufficient trading history for the Company's common stock, the expected volatility was largely estimated based on the historical equity volatility of common stock of comparable publicly traded entities over a period equal to the expected term of the stock option grants. For each of the comparable publicly traded entities, the historical equity volatility and the capital structure of the entity were used to calculate the implied stock volatility. The average implied stock volatility of the comparable publicly traded entities was then used to calculate a relevered equity volatility for the Company based on the Company’s own capital structure. Beginning in the second quarter of 2018, the Company began weighting in its own historical equity volatility to arrive at the concluded weighted-average equity volatility for the option valuation model. The comparable entities from the healthcare sector were chosen based on area of specialty. The Company will continue to apply this process until it believes a sufficient amount of historical information regarding the volatility of its own stock price becomes available. Stock‑based compensation expense for performance or service‑based stock awards is recognized over the requisite service period using the straight‑line method, which is generally the vesting period of the equity award, and is adjusted each period for actual forfeitures. The Company adopted the provision of ASU 2016-9, Compensation – Stock Compensation (Topic 718) – Improvements to Employee Share-Based Payment Accounting as of July 1, 2016. Upon early adoption, the Company elected to change its accounting policy to recognize forfeitures as they occur. The change was applied on a modified retrospective basis. See “ Note 19 - Stock-Based Compensation ” for additional discussion. For market and performance awards whose vesting is contingent upon a specified event, the Company recognizes stock compensation expense over the derived service period. Interest Rate Swap and Cap Agreements The Company holds a combination of interest rate caps and a forward interest rate swap as a means of hedging its exposure to and volatility from variable‑based interest rate changes as part of its overall interest rate risk management strategy. The agreements have the economic effect of converting the LIBOR variable component of the Company’s interest rate to a fixed rate. These agreements are designated as cash flow hedges, and as a result, hedge‑effective gains or losses resulting from changes in fair values of these instruments are reported in other comprehensive income until such time as each swap or cap is realized, at which time the amounts are reclassified to other income (expense). The instruments are perfectly effective. In the event the critical terms of the agreements no longer match the Company's exposure, the Company will measure the ineffectiveness, and record those cumulative measurements in the noncash component of interest expense. Net amounts paid or received for each swap or cap that has settled has been reflected as adjustments to interest expense. These instruments do not contain credit risk contingent features. See “ Note 15 - Debt ” for additional discussion. Gain on Business Interruption Insurance As of December 31, 2018, the Company operated 44 clinics in Florida and 26 clinics in Texas. Due to severe weather conditions in connection with Hurricanes Harvey and Irma in August 2017 and September 2017, the Company's clinic operations located in Florida and Texas were adversely impacted. During the three months ended December 31, 2018, the Company received $375 of business interruption insurance proceeds, which is included in gain on business interruption insurance within operating expenses on the consolidated statements of operations for the period then ended.

Restatement of Consolidated Fin

Restatement of Consolidated Financial Statements	12 Months Ended
	Dec. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Restatement of Consolidated Financial Statements	Restatement of Consolidated Financial Statements Restatement Background On March 21, 2019, the Board in conjunction with the management concluded that the Company's previously issued consolidated financial statements and related disclosures for the fiscal years ended December 31, 2017 and 2016 should no longer be relied upon for the reasons described below. The consolidated balance sheet as of December 31, 2017 and 2016 and the consolidated statements of operations, comprehensive income, consolidated statements of changes in shareholders’ equity and the consolidated statements of cash flows for the years ended December 31, 2017 and 2016 have been restated. The Company has also corrected certain disclosures within the consolidated financial statements related to the restatement adjustments discussed below. As a result of these adjustments, the Company has restated its consolidated financial statements as of and for the years ended December 31, 2017 and December 31, 2016 in accordance with ASC 250, Accounting Changes and Error Corrections (the “restated consolidated financial statements”). Descriptions of Restatement Adjustments The primary categories of adjustments and their impact on previously reported consolidated financial statements for 2017 and 2016 annual periods are described below: a. Revenue recognition and accounts receivable - The methodology for reserving for contractual allowances did not reconcile revenue and accounts receivable to the Company's collection experience and actual cash collections. The restated amounts consider actual cash collections associated with the dates of service in each relevant period. b. Noncontrolling interests subject to puts provisions - As a result of the restatement adjustments described in item (a) of this Note, the fair values of Noncontrolling Interest subject to puts have been revalued and restated. In addition, the Company did not correctly account for noncontrolling interests subject to put provisions during the Restated Periods, therefore the Company has reclassified certain equity balances. The reclassifications had no impact on income before income taxes or net income. c. Clinic dispositions - The gain or loss calculation for the sale and/or closure of dialysis clinics did not consider all relevant accounts. The restated amounts include the impact of all relevant accounts, including goodwill. d. Income taxes - Adjustments to income taxes were made for the income tax effects of the restatement adjustments described in item (a) of this Note. In addition, the Company did not correctly account for certain income tax provisions during the Restated Periods, causing income tax expenses and related interest to be accrued incorrectly in those periods. e. Net income attributable to noncontrolling interests - The restatement adjustments related to net income attributable to noncontrolling interests are due to the impacts of the other restatement adjustments noted above. f. Other - There are other adjustments not otherwise described in items (a) through (e) of this Note that are individually, and in the aggregate, insignificant to previously reported income from operations before income taxes. In addition, the Company made certain reclassification entries to previously reported consolidated financial statements for 2017 and 2016 annual periods, which are described below: g. Clinic dispositions - In addition to the adjustment noted in (c) above related to clinic dispositions, in certain circumstances, the Company presented the gain or loss as a component of patient care costs rather than as a component of general and administrative expenses. The Company has reclassified the adjusted gain or loss to general and administrative expenses where applicable. The reclassifications had no impact on income before income taxes or net income. h. Non-income-based tax - The Company reclassified non-income-based tax expenses that were misclassified in income tax expense to general and administrative expense and patient care costs as applicable. The reclassifications had no impact on net income. Consolidated financial statement adjustment tables The following tables present the adjustments to previously issued consolidated financial statements. This information is presented for each impacted caption of the previously reported consolidated balance sheets as of December 31, 2017 and 2016, consolidated statement of operations and comprehensive income and consolidated statements of cash flows for the years ended December 31, 2017 and 2016. The adjustments affecting fiscal years prior to 2016 are reflected as a cumulative adjustment to the balance of retained earnings as of December 31, 2015 on the consolidated statements of changes in shareholders’ equity. Following are the restated Consolidated Balance Sheets (in thousands, except per share data): As of December 31, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 71,521 $ (10 ) f $ 71,511 Accounts receivable, net of allowance for doubtful accounts 79,662 32,980 a 112,642 Inventories 4,665 — 4,665 Prepaid expenses and other current assets 24,998 — 24,998 Income tax receivable 6,745 (6,745 ) d — Total current assets 187,591 26,225 213,816 Property and equipment, net of accumulated depreciation 168,537 — 168,537 Intangible assets, net of accumulated amortization 25,368 — 25,368 Other long-term assets 9,285 — 9,285 Goodwill 573,427 (282 ) c 573,145 Total assets $ 964,208 $ 25,943 $ 990,151 Liabilities and Equity Accounts payable $ 33,421 $ — $ 33,421 Accrued compensation and benefits 28,985 — 28,985 Accrued expenses and other current liabilities 49,963 14,612 d 64,575 Current portion of long-term debt 44,534 — 44,534 Total current liabilities 156,903 14,612 171,515 Long-term debt, less current portion 515,554 — 515,554 Income tax receivable agreement payable 7,500 — 7,500 Other long-term liabilities 14,880 — 14,880 Deferred tax liabilities 8,991 (8,569 ) d 422 Total liabilities 703,828 6,043 709,871 Commitments and contingencies Noncontrolling interests subject to put provisions 139,895 (9,457 ) b 130,438 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,034,439 issued and outstanding 193 — 193 Additional paid-in capital 67,853 31,245 b,c 99,098 Receivable from noncontrolling interests (358 ) — (358 ) Accumulated deficit (123,789 ) (12,109 ) a,b,c,d,f (135,898 ) Accumulated other comprehensive income (loss), net of tax (677 ) (214 ) d (891 ) Total American Renal Associates Holdings, Inc. deficit (56,778 ) 18,922 (37,856 ) Noncontrolling interests not subject to put provisions 177,263 10,435 b 187,698 Total equity 120,485 29,357 149,842 Total liabilities and equity $ 964,208 $ 25,943 $ 990,151 As of December 31, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 100,916 $ (11 ) f $ 100,905 Accounts receivable, net of allowance for doubtful accounts 81,127 49,084 a 130,211 Inventories 4,676 — 4,676 Prepaid expenses and other current assets 18,498 — 18,498 Income tax receivable 5,163 (5,163 ) d — Total current assets 210,380 43,910 254,290 Property and equipment, net of accumulated depreciation 170,118 — 170,118 Deferred tax assets — 10,349 d 10,349 Intangible assets, net of accumulated amortization 25,626 — 25,626 Other long-term assets 6,753 — 6,753 Goodwill 573,147 (55 ) c 573,092 Total assets $ 986,024 $ 54,204 $ 1,040,228 Liabilities and Equity Accounts payable $ 31,127 $ — $ 31,127 Accrued compensation and benefits 29,103 — 29,103 Accrued expenses and other current liabilities 45,286 17,736 d 63,022 Current portion of long-term debt 48,274 — 48,274 Total current liabilities 153,790 17,736 171,526 Long-term debt, less current portion 522,058 — 522,058 Income tax receivable agreement payable 21,200 — 21,200 Other long-term liabilities 11,670 — 11,670 Deferred tax liabilities 1,278 (1,278 ) d — Total liabilities 709,996 16,458 726,454 Commitments and contingencies Noncontrolling interests subject to put provisions 130,365 19,684 b 150,049 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 30,894,962 issued and outstanding 184 — 184 Additional paid-in capital 95,062 5,625 b,c 100,687 Receivable from noncontrolling interests (544 ) — (544 ) Accumulated deficit (128,646 ) (2,655 ) a,b,c,d,f (131,301 ) Accumulated other comprehensive income (loss), net of tax (100 ) — (100 ) Total American Renal Associates Holdings, Inc. deficit (34,044 ) 2,970 (31,074 ) Noncontrolling interests not subject to put provisions 179,707 15,092 b 194,799 Total equity 145,663 18,062 163,725 Total liabilities and equity $ 986,024 $ 54,204 $ 1,040,228 Following are the restated Consolidated Statements of Operations (in thousands, except share and per share data): For the Year Ended December 31, 2017 As Previously Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 752,510 $ (15,192 ) a $ 737,318 Provision for uncollectible accounts (7,404 ) (912 ) a (8,316 ) Net patient service operating revenues 745,106 (16,104 ) 729,002 Operating expenses: Patient care costs 482,450 651 g 483,101 General and administrative 102,598 (505 ) c,g,h 102,093 Transaction-related costs 717 — 717 Depreciation and amortization 37,634 — 37,634 Certain legal and other matters 15,249 — 15,249 Total operating expenses 638,648 146 638,794 Operating income 106,458 (16,250 ) 90,208 Interest expense, net (29,289 ) (20 ) f (29,309 ) Loss on early extinguishment of debt (526 ) — (526 ) Change in fair value of income tax receivable agreement 7,234 — 7,234 Income before income taxes 83,877 (16,270 ) 67,607 Income tax expense 8,194 1,277 d,h 9,471 Net income 75,683 (17,547 ) 58,136 Less: Net income attributable to noncontrolling interests (70,826 ) 8,093 e (62,733 ) Net income (loss) attributable to American Renal Associates Holdings, Inc. 4,857 (9,454 ) (4,597 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (12,276 ) 773 b (11,503 ) Net loss attributable to common shareholders $ (7,419 ) $ (8,681 ) $ (16,100 ) Loss per share: Basic $ (0.24 ) $ (0.52 ) Diluted $ (0.24 ) $ (0.52 ) Weighted-average number of common shares outstanding Basic 31,081,824 31,081,824 Diluted 31,081,824 31,081,824 For the Year Ended December 31, 2016 As Previously Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 756,329 $ 15,892 a $ 772,221 Provision for uncollectible accounts (6,562 ) 1,121 a (5,441 ) Net patient service operating revenues 749,767 17,013 766,780 Operating expenses: Patient care costs 452,449 4 h 452,453 General and administrative 127,631 290 f,h 127,921 Transaction-related costs 2,239 — 2,239 Depreciation and amortization 33,862 — 33,862 Certain legal and other matters 6,779 — 6,779 Total operating expenses 622,960 294 623,254 Operating income 126,807 16,719 143,526 Interest expense, net (35,933 ) (26 ) f (35,959 ) Loss on early extinguishment of debt (4,708 ) — (4,708 ) Change in fair value of income tax receivable agreement 1,286 — 1,286 Income before income taxes 87,452 16,693 104,145 Income tax (benefit) expense (753 ) 3,232 d,h 2,479 Net income 88,205 13,461 101,666 Less: Net income attributable to noncontrolling interests (88,590 ) (9,930 ) e (98,520 ) Net (loss) income attributable to American Renal Associates Holdings, Inc. (385 ) 3,531 3,146 Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (7,404 ) (2,663 ) b (10,067 ) Net loss attributable to common shareholders $ (7,789 ) $ 868 $ (6,921 ) Loss per share: Basic $ (0.28 ) $ (0.25 ) Diluted $ (0.28 ) $ (0.25 ) Weighted-average number of common shares outstanding Basic 28,116,673 28,118,673 Diluted 28,116,673 28,118,673 Cash dividends declared per share $ 1.30 $ 1.30 Following are the restated Consolidated Statements of Comprehensive Income (Loss) (in thousands): For the Year Ended December 31, 2017 As Reported Restatement Adjustments Reference As Restated Net income $ 75,683 $ (17,547 ) a,c,f $ 58,136 Unrealized loss on derivative agreements, net of tax (577 ) (214 ) d (791 ) Total comprehensive income (loss) 75,106 (17,761 ) 57,345 Less: Comprehensive income attributable to noncontrolling interests (70,826 ) 8,093 e (62,733 ) Total comprehensive income (loss) attributable to American Renal Associates Holdings, Inc. $ 4,280 $ (9,668 ) $ (5,388 ) For the Year Ended December 31, 2016 As Reported Restatement Adjustments Reference As Restated Net income $ 88,205 $ 13,461 a,f $ 101,666 Unrealized gain on derivative agreements, net of tax 401 — 401 Total comprehensive income 88,606 13,461 102,067 Less: Comprehensive income attributable to noncontrolling interests (88,590 ) (9,930 ) e (98,520 ) Total comprehensive income attributable to American Renal Associates Holdings, Inc. $ 16 $ 3,531 $ 3,547 Following are the restated Consolidated Statements of Cash Flows (in thousands): For the Year Ended December 31, 2017 As Previously Reported Restatement Adjustments Reference As Restated Operating activities Net income $ 75,683 $ (17,547 ) a,c,f $ 58,136 Adjustments to reconcile net income to cash provided by operating activities: Depreciation and amortization 37,634 — 37,634 Amortization of discounts, fees and deferred financing costs 2,031 — 2,031 Loss on early extinguishment of debt 526 — 526 Stock-based compensation 15,872 — 15,872 Premium paid for interest rate cap agreements (1,186 ) — (1,186 ) Deferred taxes 8,455 2,844 d 11,299 Change in fair value of income tax receivable agreement (7,234 ) — (7,234 ) Non-cash charge related to derivative agreements 173 — 173 Non-cash rent charges 1,044 — 1,044 Loss (gain) on disposal of assets (772 ) 745 c (27 ) Change in operating assets and liabilities, net of acquisitions: Accounts receivable 1,465 16,103 a 17,568 Inventories 11 — 11 Prepaid expenses and other current assets (7,936 ) 1,583 d (6,353 ) Other assets (1,325 ) — (1,325 ) Accounts payable 2,294 — 2,294 Accrued compensation and benefits (118 ) — (118 ) Accrued expenses and other liabilities 1,930 (3,727 ) d (1,797 ) Cash provided by operating activities 128,547 1 128,548 Investing activities Purchases of property, equipment and intangible assets (36,073 ) — (36,073 ) Proceeds from asset sales 2,325 — 2,325 Cash paid for acquisitions (1,555 ) — (1,555 ) Cash used in investing activities (35,303 ) — (35,303 ) Financing activities Net proceeds from issuance of long-term debt 267,564 — 267,564 Cash paid for financing costs (3,914 ) — (3,914 ) Proceeds on term loans, net of deferred financing costs 49,921 — 49,921 Payments on long-term debt (327,331 ) — (327,331 ) Dividends and dividend equivalents paid (8,729 ) — (8,729 ) Proceeds from exercise of stock options 2,380 — 2,380 Distribution to noncontrolling interests (79,478 ) — (79,478 ) Contributions from noncontrolling interests 6,522 — 6,522 Purchases of noncontrolling interests (29,540 ) — (29,540 ) Proceeds from sales of additional noncontrolling interests 66 — 66 Cash used in financing activities (122,539 ) — (122,539 ) Decrease in cash (29,295 ) 1 f (29,294 ) Cash at beginning of year 100,916 (11 ) f 100,905 Cash at end of year $ 71,621 $ (10 ) $ 71,611 For the Year Ended December 31, 2016 As Previously Reported Restatement Adjustments Reference As Restated Operating activities Net income $ 88,205 $ 13,461 a,f $ 101,666 Adjustments to reconcile net income to cash provided by operating activities: Depreciation and amortization 33,862 — 33,862 Amortization of discounts, fees and deferred financing costs 2,595 — 2,595 Loss on early extinguishment of debt 4,708 — 4,708 Stock-based compensation 40,285 — 40,285 Deferred taxes (14,018 ) (4,552 ) d (18,570 ) Change in fair value of income tax receivable agreement (1,286 ) — (1,286 ) Non-cash charge related to derivative agreements 473 — 473 Non-cash rent charges 2,191 — 2,191 Loss (gain) on disposal of assets 857 — 857 Change in operating assets and liabilities, net of acquisitions: Accounts receivable (4,208 ) (17,013 ) a (21,221 ) Inventories (385 ) — (385 ) Prepaid expenses and other current assets (7,226 ) 2,458 d (4,768 ) Other assets (219 ) — (219 ) Accounts payable 8,556 — 8,556 Accrued compensation and benefits 6,599 — 6,599 Accrued expenses and other liabilities 11,222 5,641 d 16,863 Cash provided by operating activities 172,211 (5 ) 172,206 Investing activities Purchases of property, equipment and intangible assets (61,432 ) — (61,432 ) Cash paid for acquisitions (4,507 ) — (4,507 ) Cash used in investing activities (65,939 ) — (65,939 ) Financing activities Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense 175,254 — 175,254 Net proceeds from issuance of long-term debt 60,000 — 60,000 Cash paid for financing costs (1,350 ) — (1,350 ) Proceeds on term loans, net of deferred financing costs 70,590 — 70,590 Payments on long-term debt (275,243 ) — (275,243 ) Dividends and dividend equivalents paid (30,241 ) — (30,241 ) Proceeds from exercise of stock options 170 — 170 Common stock repurchases for tax withholdings of net settlement equity awards (356 ) — (356 ) Distribution to noncontrolling interests (94,468 ) — (94,468 ) Contributions from noncontrolling interests 7,470 — 7,470 Purchases of noncontrolling interests (8,397 ) — (8,397 ) Proceeds from sales of additional noncontrolling interests 227 — 227 Cash used in financing activities (96,344 ) — (96,344 ) Increase in cash 9,928 (5 ) f 9,923 Cash at beginning of year 90,988 (6 ) f 90,982 Cash at end of year $ 100,916 $ (11 ) $ 100,905

Initial Public Offering

Initial Public Offering	12 Months Ended
	Dec. 31, 2018
INITIAL PUBLIC OFFERING
Initial Public Offering	Initial Public Offering On April 26, 2016, the Company completed an initial public offering (the “IPO”) pursuant to which the Company sold an aggregate of 8,625,000 shares of common stock at a public offering price of $22.00 per share. The net proceeds to the Company from its sale of shares of common stock in the IPO, after deducting underwriting discounts and before deducting offering expenses, amounted to $176,942 . The Company applied $165,635 of the net proceeds from the IPO toward repayment of outstanding amounts under its second lien credit facility, and funded the repayment in full of the outstanding balance with borrowings from its first lien credit facility, as amended, and cash on hand. In connection to the IPO and the debt repayment, the Company incurred $2,239 of transaction-related costs for various legal, accounting, valuation and other professional and consulting services during the twelve months ended December 31, 2016. Amendment of Certificate of Incorporation On April 7, 2016, the Company’s board of directors authorized the amendment of its certificate of incorporation to increase the number of shares that the Company is authorized to issue to 300,000,000 shares of common stock, par value $0.01 per share. In addition, the amendment of the certificate of incorporation authorized the Company to effect a 2.29 -for-one stock split of its outstanding common stock. The amendment became effective on April 26, 2016. Accordingly, all common share and per share amounts in these consolidated financial statements have been adjusted to reflect the 2.29 -for-one stock split as though it had occurred at the beginning of the initial period presented. Clinic Loan Assignment and Term Loan Holdings LLC Distribution The Company partly finances clinic development costs of some of its JV subsidiaries by providing intercompany term loans and revolving loans through its wholly owned operating subsidiary American Renal Associates LLC (“ARA OpCo”). On April 26, 2016, the Company transferred substantially all of the then existing intercompany term loans (“Assigned Clinic Loans”) provided to its JV subsidiaries by ARA OpCo to a newly formed entity, Term Loan Holdings LLC (“Term Loan Holdings”), which ownership interest was distributed to pre-IPO stockholders (affiliates of Centerbridge and certain of the Company's current and former directors and executive officers) pro rata in accordance with their then ownership in the Company (the “Term Loan Holdings Distribution”). Each assigned clinic loan is guaranteed by the Company and the applicable joint venture partner or partners in proportion to their respective ownership interests in the applicable JV. These guarantees would become payable if the joint venture fails to meet its obligations under the applicable Assigned Clinic Loan. Assigned Clinic Loans are reflected on the consolidated balance sheet as $5,078 , $11,082 , and $19,768 as of December 31, 2018 , 2017 , and 2016 , respectively, and had maturities ranging from February 2019 to July 2020 , with a weighted average maturity of approximately 0.9 years ( December 2019 ), and interest rates ranging from 4.25% to 8.08% , with a weighted average interest rate of 5.12% . Fixed principal and interest payments with respect to such Assigned Clinic Loans are payable monthly. The pro rata share of the guarantee was $2,813 , $5,854 , and $10,473 as of December 31, 2018 , 2017 , and 2016 , respectively. See “ Note 15 - Debt ” and “ Note 20 - Related Party Transactions .” Amendments to and Repayment of Credit Facility On April 26, 2016, the Company entered into the first amendment (the “Amendment”) to the First Lien Credit Agreement. The Amendment increased the borrowing capacity under the first lien revolving credit facility by $50,000 to an aggregate amount of $100,000 , increased the interest rate margin by 0.25% on the first lien term loans, and provided for additional borrowings of $60,000 of incremental first lien term loans. The Company incurred $2,700 of costs associated with these refinancing activities, of which $1,350 were charged as transaction costs and $1,350 were deferred upon execution of the Amendment and amortized over the life of the First Lien Credit Agreement. The Company also applied $165,635 of the net proceeds from the IPO and cash on hand to repay the outstanding balance on the second lien term loans. The write-off of deferred financing fees and discounts in the amount of $4,708 were charged as early extinguishment of debt upon repayment. Income Tax Receivable Agreement On April 26, 2016, the Company entered into the Income Tax Receivable Agreement (“TRA”) for the benefit of its pre-IPO stockholders, including Centerbridge and its executive officers. The TRA provides for the Company to pay its pre-IPO stockholders on a pro rata basis of 85% of the amount of cash savings, if any, in U.S. federal, state and local income tax that are actually realized as a result of any deductions (including net operating losses resulting from such deductions) attributable to the exercise of (or any payment, including any dividend equivalent right or payment, in respect of ) any compensatory stock option issued by us that is outstanding (whether vested or unvested) as of April 20, 2016, which is the record date set by the board of directors of the Company for this distribution. The Company recorded an estimated liability of $23,400 based on the fair value of the TRA as of April 20, 2016. As of December 31, 2018 , the Company’s total liability under the TRA is estimated to be $4,952 , including the fair value of the financial instrument of $3,700 as well as $1,252 of accrued but unpaid obligations, included as a component of other accrued expenses on the consolidated balance sheet. During the years ended December 31, 2018 and 2017 the Company paid $6,376 and $878 , respectively, relating to the TRA. See “ Note 8 - Fair Value Measurements .” Special Dividends and Stock Option Modification On April 26, 2016, the Company declared and paid a cash dividend to its pre-IPO stockholders equal to $1.30 per share, or $28,886 in the aggregate. In connection with the dividend, all employees with outstanding options had their option exercise price reduced and in some cases were awarded a future dividend equivalent payment, which was paid on vested options and becomes due upon vesting for unvested options. Additionally, in connection with the cash dividend, through December 31, 2018 the Company has made payments equal to $1.30 per share, or $5,341 in the aggregate, to option holders, and, in the case of some performance and market options, a future payment totaling $1,385 will be due upon vesting. In connection with the Term Loan Holdings Distribution, as described above, the Company also equitably adjusted certain outstanding stock options by reducing exercise prices and making cash dividend equivalent payments, of which $2,524 was paid to vested option holders through December 31, 2018 and an immaterial amount is payable to unvested option holders only if such unvested options become vested. Options were also equitably adjusted for the TRA, as described above. Options were adjusted by reducing exercise prices and, if necessary, increasing the number of shares subject to such stock options. In connection with these dividends, equitable adjustments are required by the terms of some of the Company's equity incentive plans and other plans were modified at the discretion of its Board of Directors. The Company also elected to modify the vesting conditions of certain market and performance-based stock options. These modifications are treated as an option modification and the Company accounted for the option modification under ASC Topic 718, Compensation – Stock Compensation. As a result of these modifications made to the Company's outstanding market and performance-based stock options at the time of the IPO, the amount of the non-cash compensation costs increased by approximately $38,877 . These compensation costs, after giving effect to the modifications, were recognized over a period of approximately 12 months from the time of the IPO. As a result, the Company recognized $ 11,749 and $36,368 in incremental compensation expense during the years ended December 31, 2017 and 2016, respectively. The Company also incurred $586 of stock compensation expense due to transactions at the time of the IPO during the year ended December 31, 2016.

Cash

Cash	12 Months Ended
	Dec. 31, 2018
Cash and Cash Equivalents [Abstract]
Cash	Cash The following table provides a reconciliation of cash and restricted cash reported within the balance sheet to the total shown in the statement of cash flows. December 31, 2018 December 31, 2017 December 31, 2016 (restated) (restated) Cash $ 55,200 $ 71,511 $ 100,905 Restricted cash included in other long-term assets 100 100 — Total cash and restricted cash shown in the statement of cash flows $ 55,300 $ 71,611 $ 100,905 Restricted cash included in other long-term assets on the balance sheet represent those amounts required to be set aside by contractual agreement with a financial institution.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following at December 31 : 2018 2017 2016 Medicare recovery claims $ 10,622 $ 10,744 $ 9,224 Prepaid expenses and other 17,505 14,254 9,274 $ 28,127 $ 24,998 $ 18,498

Acquisitions and Divestitures

Acquisitions and Divestitures	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Acquisitions and Divestitures	Acquisitions and Divestitures Acquisitions The Company periodically acquires the operating assets and liabilities of dialysis centers. The results of operations for these acquisitions are included in the Company’s consolidated statements of operations from their respective acquisition consummation dates. Fiscal Year 2018 On November 1, 2018, the Company acquired the assets of a dialysis center in California. The company has a controlling interest in the joint venture. The cash consideration paid was preliminarily based on the estimated fair value, as follows: Property and equipment $ 329 Other assets 59 Cash consideration paid $ 388 This acquisition was made to expand the Company’s market presence in California. Pro forma information is not presented because such amounts are not significant. Fiscal Year 2017 On November 1, 2017, the Company acquired the assets of two separate dialysis centers in Oklahoma. The Company has a controlling interest in these joint ventures. On December 1, 2017, the Company acquired the assets of a dialysis center in Georgia. The Company has a controlling interest in the joint venture. The cash consideration paid, on a combined basis for all acquisitions consummated during 2017 , was allocated based on the estimated fair value, as follows: Property and equipment $ 737 Noncompete agreements and other intangible assets 93 Goodwill 725 Cash consideration paid $ 1,555 These acquisitions were made to expand the Company’s market presence in the indicated locations. The goodwill arising from these acquisitions is primarily attributable to future growth opportunities and any intangible assets that did not qualify for separate recognition, and $647 of the goodwill is deductible for tax purposes. These acquisitions, individually and in the aggregate, had an immaterial impact on the results of operations in the year of acquisition. Pro forma information is not presented because such amounts are not significant. Fiscal Year 2016 On April 11, 2016, the Company acquired the assets of a dialysis center in New York. The Company has a controlling interest in the joint venture. On September 1, 2016, the Company acquired the assets of two separate dialysis centers in Pennsylvania. The Company has a controlling interest in these joint ventures. One of the Pennsylvania dialysis centers was not in operation immediately prior to the acquisition, and therefore required a new Medicare license to restart operations. The cash consideration paid, on a combined basis for all acquisitions consummated during 2016 , was allocated based on the estimated fair value, as follows: Property and equipment $ 400 Noncompete agreements and other intangible assets 268 Goodwill 3,839 Cash consideration paid $ 4,507 These acquisitions were made to expand the Company’s market presence in the indicated locations. The goodwill arising from these acquisitions is primarily attributable to future growth opportunities and any intangible assets that did not qualify for separate recognition, and $3,723 of the goodwill is deductible for tax purposes. These acquisitions, individually and in the aggregate, had an immaterial impact on the results of operations in the year of acquisition. Pro forma information is not presented because such amounts are not significant. Divestitures The Company periodically divests the operating assets and liabilities of dialysis centers. The results of operations for these divestitures are included in the Company’s consolidated statements of operations through their respective sale consummation dates. Fiscal Year 2018 On March 1, 2018, the Company sold 100% of its equity in a dialysis clinic in Florida and received cash consideration for the sale of $2,500 . The transaction resulted in the recognition of a gain of $262 related to the sale of the clinic and its derecognition which is included as a reduction to general and administrative expenses to arrive at operating income in the condensed consolidated statements of operations for the year ended December 31, 2018 and a reduction of goodwill of $1,806 . Fiscal Year 2017 On June 2, 2017, the Company sold 100% of its equity in a dialysis clinic in Massachusetts and on August 1, 2017, the Company sold 100% of its equity in a dialysis clinic in Florida for a combined cash consideration of $1,075 . The transactions resulted in the recognition of a combined gain of $615 related to the sale of the clinics and their derecognition which is included as a reduction to general and administrative expenses to arrive at operating income in the condensed consolidated statements of operations for the year ended December 31, 2017 and a reduction of goodwill of $563 . The Company also closed four clinics during the year ended December 31, 2017 for a combined loss of $107 and a reduction of goodwill of $109 . Fiscal Year 2016 None.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company’s derivatives (interest rate swap and interest rate cap agreements, TRA and noncontrolling interests subject to put provisions) are accounted for at fair value and are classified and disclosed in one of the following three categories: Level 1: Financial instruments with unadjusted, quoted prices listed on active market exchanges. Level 2: Financial instruments determined using prices for recently traded financial instruments with similar underlying terms, as well as directly or indirectly observable inputs, such as interest rates and yield curves that are observable at commonly quoted intervals. Level 3: Financial instruments not actively traded on a market exchange. This category includes situations where there is little, if any, market activity for the financial instrument. The prices are determined using significant unobservable inputs or valuation techniques. The asset or liability fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. There were no changes in the methodologies used at December 31, 2018 . Derivative agreements — See “ Note 15 - Debt ” for a discussion of the Company’s methodology for estimating fair value of interest rate swap and interest rate cap agreements. Income Tax Receivable Agreement —The fair value of the Company's TRA relies upon both Level 2 data and Level 3 data. The liability is remeasured at fair value each reporting period with the change in fair value recognized as Change in fair value of income tax receivable agreement in the Company’s Consolidated Statements of Operations. The fair value is calculated using a Monte Carlo simulation-based approach that relies on significant assumptions about the Company's stock price, stock volatility and risk-free rate as well as the timing and amounts of options exercised. Changes in assumptions based on future events, including the price of the Company's common stock, will impact the fair value for the TRA. See “ Note 4 - Initial Public Offering ” for further discussion of the TRA. Noncontrolling interests subject to put provisions — See “ Note 13 - Noncontrolling Interests Subject to Put Provisions ” for a discussion of the Company’s methodology for estimating fair value of noncontrolling interest subject to put provisions. Transfers among levels are calculated on values as of the transfer date. There were no transfers between Levels 1, 2 and 3 during the years ended December 31, 2018 , 2017 , and 2016 . December 31, 2018 Total Level 1 Level 2 Level 3 Assets Interest rate derivative agreements (included in Prepaid expenses and other current assets) $ 836 $ — $ 836 $ — Interest rate derivative agreements (included in Other long-term assets) 395 — 395 — Total Assets $ 1,231 $ — $ 1,231 $ — Liabilities Tax Receivable Agreement Liability (included in Income tax receivable agreement payable) $ 3,700 $ — $ — $ 3,700 Total Liabilities $ 3,700 $ — $ — $ 3,700 Temporary Equity Noncontrolling interests subject to put provisions $ 129,099 $ — $ — $ 129,099 December 31, 2017 Total Level 1 Level 2 Level 3 Assets Interest rate derivative agreements (included in Prepaid expenses and other current assets) $ 46 $ — $ 46 $ — Interest rate derivative agreements (included in Other long-term assets) 255 — 255 — Total Assets $ 301 $ — $ 301 $ — Liabilities Tax Receivable Agreement Liability (included in Income tax receivable agreement payable) $ 7,500 $ — $ — $ 7,500 Interest rate derivative agreements (included in Accrued expense and other current liabilities) 403 — 403 — Interest rate derivative agreements (included in Other long-term liabilities) 198 — 198 — Total Liabilities $ 8,101 $ — $ 601 $ 7,500 Temporary Equity Noncontrolling interests subject to put provisions(1) $ 130,438 $ — $ — $ 130,438 December 31, 2016 Total Level 1 Level 2 Level 3 Assets Interest rate swap agreements (included in Prepaid expenses and other current assets) $ 7 $ — $ 7 $ — Liabilities Tax Receivable Agreement Liability (included in Income tax receivable agreement payable) $ 21,200 $ — $ — $ 21,200 Temporary Equity Noncontrolling interests subject to put provisions(1) $ 150,049 $ — $ — $ 150,049 (1) Adjusted to reflect the restatement of the Company's financial results. The following table provides the fair value rollforward for the TRA liability, which is classified as a Level 3 financial instrument. Balance at January 1, 2016 — Initial fair value as of April 20, 2016 23,400 Options exercised and dividend equivalent payment vesting (914 ) Total realized/unrealized gains: Included in earnings and reported as Change in fair value of income tax receivable agreement $ (1,286 ) Balance at December 31, 2016 $ 21,200 Options exercised and dividend equivalent payment vesting (6,466 ) Total realized/unrealized gains: Included in earnings and reported as Change in fair value of income tax receivable agreement (7,234 ) Balance at December 31, 2017 $ 7,500 Options exercised and dividend equivalent payment vesting (1,127 ) Total realized/unrealized gains: Included in earnings and reported as Change in fair value of income tax receivable agreement (2,673 ) Balance at December 31, 2018 $ 3,700 The carrying amounts reported in the accompanying consolidated balance sheets for cash, accounts receivable, accounts payable and accrued liabilities approximate fair value because of their short‑term nature. The fair value of the Company’s debt is estimated using Level 2 inputs based on the quoted market prices for the same or similar issues or on the current rates offered to the Company for debt of the same remaining maturities. The Company estimated the fair value of the first lien term loans to be $424,732 as of December 31, 2018 compared to a carrying value of $433,400 . As of December 31, 2017 , the Company estimated the fair value of the first lien term loans to be $436,158 compared to the carrying value of $437,800 . The Company estimated the fair value of its then-outstanding first lien term loans approximated the carrying value at $433,758 as of December 31, 2016 .

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment consist of the following at December 31 : 2018 2017 2016 Land $ 2,030 $ 2,030 $ 2,203 Buildings and improvements 8,197 2,904 3,425 Leasehold improvements 201,445 178,569 154,783 Equipment and information systems 162,750 145,514 125,813 Construction in progress 5,549 6,910 5,136 379,971 335,927 291,360 Less accumulated depreciation (199,703 ) (167,390 ) (121,242 ) $ 180,268 $ 168,537 $ 170,118 Depreciation of property and equipment totaled $39,004 in 2018 , $37,045 in 2017 , and $32,837 in 2016. Included in construction in progress are amounts expended for leasehold improvement costs incurred for new dialysis clinics and clinic expansions, in each case, that are not in service as of December 31 of the applicable year. The cost and accumulated amortization of assets under capital leases included in Buildings and improvements above at December 31, 2018 were $6,381 and $213 , respectively. There were no capital leases in 2017 or 2016. The Company also has $477 of property and equipment, net classified as Current assets held for sale as of December 31, 2018 related to the sale of certain clinics in Maryland which was executed on July 1, 2019 and met the held for sale criteria as of December 31, 2018. Refer to “ Note 25 - Subsequent Events ” for further discussion related to the clinic divestitures.

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	Intangible Assets and Goodwill Intangible assets consist of the following at December 31 : 2018 2017 2016 Noncompete agreements $ 24,370 $ 24,380 $ 24,928 Other intangible assets 3,130 3,073 2,853 27,500 27,453 27,781 Less accumulated amortization (24,206 ) (23,419 ) (23,489 ) Net intangible assets subject to amortization 3,294 4,034 4,292 Indefinite‑lived trademarks and trade name 21,334 21,334 21,334 $ 24,628 $ 25,368 $ 25,626 Amortization of intangible assets totaled $798 , $589 , and $1,025 in 2018 , 2017 , and 2016 , respectively. The estimated annual amortization expense related to amortizable intangible assets is as follows for the years ending December 31 : 2019 $ 747 2020 665 2021 615 2022 470 2023 220 Thereafter 577 $ 3,294 Changes in the value of goodwill: Balance at January 1, 2016, as restated $ 569,264 Acquisitions 3,839 Subsequent adjustment for prior year acquisition (11 ) Balance at December 31, 2016, as restated $ 573,092 Acquisitions 725 Divestitures (672 ) Balance as of December 31, 2017, as restated $ 573,145 Divestitures (1,806 ) Balance at December 31, 2018 $ 571,339

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2018
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued compensation and benefits consist of the following at December 31 : 2018 2017 2016 Accrued compensation $ 22,480 $ 17,987 $ 18,077 Accrued vacation pay 12,107 10,998 11,026 $ 34,587 $ 28,985 $ 29,103 Accrued expenses and other current liabilities consist of the following at December 31 : 2018 2017 2016 (restated) (restated) Due to payors $ 26,659 $ 28,935 $ 32,902 Income tax payable 13,618 14,654 17,851 Other 13,198 20,986 12,269 Accrued Settlement (Note 22) 7,641 — — $ 61,116 $ 64,575 $ 63,022

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2018
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entities	Variable Interest Entities The Company has determined that all of the entities it is associated with that qualify as VIEs must be included in its consolidated financial statements. For its joint ventures, the Company has determined that contractual rights granted to it provide the Company with the ability to direct the most significant activities of these entities, including development, administrative and management services. In some cases, the contractual agreements include financial terms that may result in the Company absorbing more than an insignificant amount of the entities' expected losses. Therefore, the Company has determined that it is the primary beneficiary of these entities. Accordingly, the financial results of these joint ventures are fully consolidated into the Company’s operating results. The equity interests of the outside investors in the equity and results of operations of these consolidated entities are accounted for and presented as noncontrolling interests. Under U.S. GAAP, VIEs typically include entities for which (i) the entity’s equity is not sufficient to finance its activities without additional subordinated financial support; (ii) the equity holders as a group lack the power to direct the activities that most significantly influence the entity’s economic performance, the obligation to absorb the entity’s expected losses, or the right to receive the entity’s expected returns; or (iii) the voting rights of some investors are not proportional to their obligations to absorb the entity’s losses. The analysis upon which these consolidation determinations rest is complex, involves uncertainties, and requires significant judgment on various matters, some of which could be subject to different interpretations. The Company relies on the operating activities of certain entities for which it does not own the majority voting interest, but over which it has indirect influence and of which it is considered the primary beneficiary. These entities are subject to the consolidation guidance applicable to variable interest entities (“VIEs”). As of December 31, 2018 , these consolidated financial statements include total assets of these VIEs $16,669 and total liabilities of these VIEs $9,038 . Term Loan Holdings The Company has determined that it is not the primary beneficiary under VIE accounting guidance for Term Loan Holdings, as discussed in “ Note 4 - Initial Public Offering .” Based on its involvement with Term Loan Holdings, the Company does not have the power to direct the activities which most significantly impact Term Loan Holding’s economic performance, and therefore this entity is not included in the Company's consolidated financial statements. The Company’s financial responsibility to repay the loans under its guarantee of a proportionate share of each clinic’s borrowing was not a factor in the Company’s assessment of the power criterion. The maximum exposure to loss with respect to Term Loan Holdings is limited to the proportion of the Assigned Clinic Loans which the Company guarantees. See “ Note 20 - Related Party Transactions .”

Noncontrolling Interests Subjec

Noncontrolling Interests Subject to Put Provisions	12 Months Ended
	Dec. 31, 2018
Temporary Equity Disclosure [Abstract]
Noncontrolling Interests Subject to Put Provisions	Noncontrolling Interests Subject to Put Provisions The Company has potential obligations to purchase a portion or all of the noncontrolling interests held by third parties in certain of its consolidated subsidiaries. These obligations are in the form of put provisions and are exercisable at the third-party owners’ discretion within specified periods as outlined in each specific put provision. Additionally, the Company has certain agreements with put provisions which are exercisable upon the occurrence of specific events, including the sale of all or substantially all of the Company's assets, closure of the clinic, change of control, departure of key executives, third-party members’ death, disability, bankruptcy, retirement, or if third-party members are dissolved and other events, which could accelerate vesting of the put. The Company has evaluated the applicable terms and determined that none of the put rights are mandatorily redeemable. Some of these put rights accelerated as a result of the Company’s IPO, of which some were exercised during the year ended December 31, 2018 . If the remaining unexercised put rights were exercised, the Company would be required to purchase all or a portion of the third-party owners’ noncontrolling interests at the estimated fair value as defined within the put provisions. The majority of the equity subject to put provisions is reported at the greater of the carrying value or estimated fair value for accounting purposes, while some of the equity subject to put provisions is stated at the contractual estimated fair value or redemption value, as outlined in each specific put provision. The put rights of such noncontrolling interest holders were determined based on inputs that are not readily available in public markets or able to be derived from information available in publicly quoted markets. As such, the Company categorized the put options of the noncontrolling interest holders as Level 3. The fair value of the noncontrolling interests subject to these put provisions is estimated using the Income, Market and Asset Based Approaches. The fair value derived from the methods used is evaluated and weighted, as appropriate, considering the reasonableness of the range of values indicated. Under the income approach, fair value may be determined by utilizing a Weighted Average Cost of Capital ( 14.50% - 20.50% ) to discount the expected cash flows to a single present value amount using current expectations about those future amounts. Under the market approach, fair value may be determined by reference to multiples of market-comparable companies or transactions, including revenue and earnings before interest, taxes, depreciation and amortization (“EBITDA”) multiples. The estimated fair values of the interests subject to these put provisions can also fluctuate and the implicit multiples at which these obligations may be settled may vary depending upon market conditions and access to the credit and capital markets, which can impact the level of competition for dialysis and non-dialysis related businesses and the economic performance of these businesses. As of December 31, 2018 , 2017 , and 2016 , the Company’s potential obligations under time‑based put provisions totaled approximately $101,115 , $97,650 , and $108,774 , respectively. As of December 31, 2018 , 2017 , and 2016 , the Company’s potential additional obligations under event‑based put provisions were approximately $27,984 , $32,788 , and $41,275 , respectively. The Company’s potential obligations for all of these put provisions are included in noncontrolling interests subject to put provisions in the accompanying consolidated balance sheets. The Company's computation of the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests as of December 31, 2018 , 2017 , and 2016 is set forth below. December 31, 2018 December 31, 2017 December 31, 2016 (restated) (restated) Redemption value $ 11,221 $ 12,283 $ 20,491 Estimated fair values for accounting purposes 2,672 5,970 10,424 Difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests $ 8,549 $ 6,313 $ 10,067 In addition, the tables below set forth a reconciliation of noncontrolling interests subject to put provisions. December 31, 2018 December 31, 2017 December 31, 2016 (restated) (restated) Noncontrolling interest subject to put provisions - estimated fair values $ 120,550 $ 124,125 $ 139,982 Difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests 8,549 6,313 10,067 Noncontrolling interests subject to put provisions - maximum redemption value $ 129,099 $ 130,438 $ 150,049 Year ended December 31, 2018 Year ended December 31, 2017 Year ended December 31, 2016 (restated) (restated) Change in estimated fair values for accounting purposes $ (9,963 ) $ (1,886 ) $ 17,415 Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests 2,566 11,503 10,067 Total change in fair value of noncontrolling interests subject to put provisions - maximum redemption $ (7,397 ) $ 9,617 $ 27,482

Changes in Ownership Interest i

Changes in Ownership Interest in Consolidated Subsidiaries	12 Months Ended
	Dec. 31, 2018
CHANGES IN OWNERSHIP INTEREST IN CONSOLIDATED SUBSIDIARIES
Changes in Ownership Interest in Consolidated Subsidiaries	Changes in Ownership Interest in Consolidated Subsidiaries The effects of changes in the Company’s ownership interests in its consolidated subsidiaries on the Company’s equity are as follows: Year ended December 31, 2018 2017 2016 (restated) (restated) Net (loss) income attributable to American Renal Associates Holdings, Inc. $ (28,767 ) $ (4,597 ) $ 3,146 (Decrease) increase in paid-in capital for the sales of noncontrolling interest (891 ) 231 99 Decrease in paid-in capital for the purchase of noncontrolling interest and adjustments to ownership interest (6,645 ) (7,566 ) (7,680 ) Net transfers to noncontrolling interests (7,536 ) (7,335 ) (7,581 ) Net loss attributable to American Renal Associates Holdings, Inc., net of transfers to noncontrolling interests $ (36,303 ) $ (11,932 ) $ (4,435 )

Debt

Debt	12 Months Ended
	Dec. 31, 2018
Debt Instruments [Abstract]
Debt	Debt Long‑term debt consists of the following at December 31 : 2018 2017 2016 2017 Credit Agreement - Term B Loan Facility $ 433,400 $ 437,800 $ 433,758 2017 Credit Agreement - Revolving Credit Facility 5,500 — — Assigned Clinic Loans due to Term Loan Holdings(1) 5,078 11,082 19,768 Other Term Loans(2) 113,866 114,536 98,735 Other Lines of Credit(3) 1,849 3,600 19,360 Capital Lease Obligations(4) 6,706 — — Other(5) 2,040 2,601 3,041 568,439 569,619 574,662 Less: discounts and fees, net of accumulated amortization (8,073 ) (9,531 ) (4,330 ) Less: current maturities (42,855 ) (44,534 ) (48,274 ) $ 517,511 $ 515,554 $ 522,058 (1) See “ Note 4 - Initial Public Offering ” and “ Note 20 - Related Party Transactions .” (2) Principal and interest is payable monthly at rates between 3.31% and 7.98% over varying periods through June 2026. (3) The interest on the lines of credit is payable monthly at rates between 4.13% and 5.13% and convert to term loans at various maturity dates through August 2022. (4) Capital lease obligations expiring in various years through 2033. (5) Principal and interest of the other corporate debt is payable monthly at a rate of 4.07% maturing in April 2022. Scheduled maturities of long‑term debt as of December 31, 2018 are as follows: 2019 $ 43,022 2020 35,761 2021 26,461 2022 23,956 2023 15,128 Thereafter 424,111 $ 568,439 During the year ended December 31, 2018 , the Company made mandatory principal payments of $4,400 under the 2017 Credit Agreement (as defined below). As of December 31, 2018 , there were $5,500 of borrowings outstanding under the 2017 Revolving Credit Facility as provided for under the Company's 2017 Credit Agreement (as defined below). 2017 Credit Agreement and Repayment of First Lien Credit Agreement On June 22, 2017, ARH and American Renal Holdings Intermediate Company, LLC (“ARHIC”) entered into a new credit agreement (the “2017 Credit Agreement”) to refinance the credit facilities under ARH's prior existing First Lien Credit Agreement. The 2017 Credit Agreement provides ARH with (a) a $100,000 senior secured revolving credit facility (the “2017 Revolving Credit Facility”); (b) a $440,000 senior secured term B loan facility (the “2017 Term B Loan Facility”), and (c) an uncommitted incremental accordion facility equal to the sum of the greater of (i) $125,000 or (ii) 100% of Consolidated EBITDA (as defined in the 2017 Credit Agreement) plus an amount such that certain leverage ratios will not be exceeded after giving pro forma effect to the increase. ARH borrowed the full amount of the 2017 Term B Loan Facility and used such borrowings to repay the outstanding balances under the First Lien Credit Agreement and to pay a portion of the transaction costs and expenses. The obligations of ARH under the 2017 Credit Agreement are guaranteed by ARHIC and all of its existing and future wholly owned domestic subsidiaries (collectively, the “Guarantors”) and secured by a pledge of all of ARH’s capital stock and substantially all of the assets of ARH and the Guarantors, including their respective interests in their joint ventures. The 2017 Credit Agreement contains customary events of default, the occurrence of which would permit the lenders to accelerate payment of the full amounts outstanding. Additionally, the 2017 Credit Agreement contains customary representations and warranties, affirmative covenants and negative covenants, including restrictive financial and operating covenants. These include covenants that restrict ARH's and its restricted subsidiaries’ ability to complete acquisitions, pay cash dividends, incur indebtedness, make investments, sell assets and take certain other corporate actions. The 2017 Credit Agreement events of default, representations and warranties, mandatory prepayments and affirmative and negative covenants are substantially the same as those under the prior first lien credit agreement; provided that the 2017 Credit Agreement contains additional exceptions to the negative covenants that increase the amount ARH and its restricted subsidiaries can use to make restricted payments and increases the flexibility for ARH and its restricted subsidiaries to undertake permitted acquisitions. As of December 31, 2018 , ARH is in compliance with these covenants. The Company incurred $9,259 of costs associated with these refinancing activities, of which $717 were charged as transaction costs, $4,628 represent debt discounts and $3,914 were deferred as financing costs upon the execution of the 2017 Credit Agreement. The debt discounts and deferred financing costs were amortized over the term of the 2017 Credit Agreement. The write-off of deferred financing fees and discounts in the amount of $526 was charged as early extinguishment of debt in 2017. 2017 Term B Loan Facility The term B loans under the 2017 Term B Loan Facility bear interest at a rate equal to, at ARH’s option, either (a) an alternate base rate equal to the higher of (1) the prime rate in effect on such day, (2) the federal funds effective rate plus 0.5% or (3) the Eurodollar rate applicable for a one-month interest period plus 1.0% , plus an applicable margin of 2.25% , (collectively, the “ABR Rate”) or (b) LIBOR, adjusted for changes in Eurodollar reserves, plus a margin of 3.25% . As of December 31, 2018 , interest payable quarterly was 5.77% per annum. The 2017 Term B Loan Facility matures in June 2024. The 2017 Credit Agreement includes provisions requiring ARH to offer to prepay term B loans in an amount equal to (i) the net cash proceeds above certain thresholds received from (a) asset sales and (b) casualty events resulting in the receipt of insurance proceeds, subject to customary provisions for the reinvestment of such proceeds, (ii) the net cash proceeds from the incurrence of debt not otherwise permitted under the 2017 Credit Agreement, and (iii) a percentage of consolidated excess cash flow retained in the business from the preceding fiscal year minus voluntary prepayments. There is no prepayment required as of December 31, 2018 . ARH is required to make principal payments under the 2017 Term B Loan Facility in equal quarterly installments of $1,100 . 2017 Revolving Credit Facility The 2017 Revolving Credit Facility of $100,000 is available through its maturity date of June 2022. Any outstanding loans under the 2017 Revolving Credit Facility bear interest at a rate equal to, at ARH’s option, the ABR Rate or LIBOR, adjusted for changes in Eurodollar reserves, plus, in each case, an applicable margin priced off a grid based upon the consolidated total net leverage ratio of ARH and its restricted subsidiaries. The commitment fee applicable to undrawn revolving commitments under the 2017 Revolving Credit Facility is also priced off a grid based upon the consolidated total net leverage ratio of ARH and its restricted subsidiaries, and as of December 31, 2018 , the fee was 0.50% . There were $5,500 borrowings outstanding under the 2017 Revolving Credit Facility as of December 31, 2018 which had an interest rate of 4.86% . The 2017 Credit Agreement was amended in April 2019. See "-Debt Related Subsequent Events" below . Interest Rate Swap Agreement In March 2017, ARH entered into a forward starting interest rate swap agreement (the “2017 Swap”) with a notional amount of $133,000 , as a means of fixing the floating interest rate component on $440,000 of its variable-rate debt under the 2017 Term B Loan Facility, with an effective date of March 31, 2018. The 2017 Swap is designated as a cash flow hedge, with a termination date of March 31, 2021. As a result of the application of hedge accounting treatment, to the extent the 2017 Swap is effective, the unrealized gains and losses related to the derivative instrument are recorded in accumulated other comprehensive income (loss) and are reclassified into operations in the same period in which the hedged transaction affects earnings, and to the extent the swap is ineffective and produces gains and losses differently from the losses or gains being hedged, the ineffectiveness portion is recognized in earnings, immediately. Hedge effectiveness is tested quarterly. Neither the Company nor ARH uses derivative instruments for trading or speculative purposes. The unrealized pre‑tax (gain) loss of $(892) , $601 , and $(668) related to interest rate swap agreements was recorded in accumulated other comprehensive income during the years ended December 31, 2018 , 2017 , and 2016, respectively. See “ Note 8 - Fair Value Measurements ” for the fair value of the derivative instruments and location on the balance sheet as of December 31, 2018 , 2017 , and 2016. Interest Rate Cap Agreements In March 2017, ARH entered into two interest rate cap agreements (the “Caps”) with notional amounts totaling $147,000 , as a means of capping the floating interest rate component on $440,000 of its variable‑rate debt under the 2017 Term B Loan Facility. The Caps are designated as a cash flow hedge, with a termination date of March 31, 2021. As a result of the application of hedge accounting treatment, to the extent the Caps are effective, the unrealized gains and losses related to the derivative instrument are recorded in accumulated other comprehensive income (loss) and are reclassified into operations in the same period in which the hedged transaction affects earnings and to the extent the Caps are ineffective and produce gains and losses differently from the losses or gains being hedged, the ineffective portion is recognized in earnings, immediately. Hedge effectiveness is tested quarterly. Neither the Company nor ARH uses derivative instruments for trading or speculative purposes. As more fully described within “ Note 8 - Fair Value Measurements ,” the Company uses a three‑level fair value hierarchy that prioritizes the inputs used to measure fair value. The fair value of the derivative instruments are recorded at fair value based upon valuation models utilizing the income approach and commonly accepted valuation techniques that use inputs from closing prices for similar assets and liabilities in active markets as well as other relevant observable market inputs at quoted intervals such as current interest rates, forward yield curves, and implied volatility. The Company does not believe the ultimate amount that could be realized upon settlement would be materially different from the fair values currently reported. The associated unrealized pre‑tax loss of $586 and $884 was recorded in accumulated other comprehensive income during the years ended December 31, 2018 and 2017 , respectively. The Company had no interest rate Cap agreements in 2016. See “ Note 8 - Fair Value Measurements ” for the fair value of the derivative instruments and location on the balance sheet as of December 31, 2018 , 2017 , and 2016. Debt Related Subsequent Events Subsequent Amendments and Waivers Related to Credit Agreement On April 26, 2019, ARH entered into an amendment (the “Amendment”) to the 2017 Credit Agreement, waiving certain actual or potential defaults and amending certain covenants and other provisions. Among other things, the waiver addressed actual or potential defaults that may have resulted from the Company's failure to (i) satisfy the maximum consolidated net leverage ratio when required, and (ii) deliver when required certain financial information for the fiscal years ended December 31, 2017 and December 31, 2018 and for the fiscal quarters ended June 30, 2017, September 30, 2017, March 31, 2018, June 30, 2018, September 30, 2018, March 31, 2019 and June 30, 2019, in each case prepared in accordance with GAAP. In connection with the Amendment, the Company paid $6,021 of fees during the quarter ended June 30, 2019 and agreed to increase the interest rate on borrowings under the 2017 Credit Agreement. The 2017 Revolving Credit Facility is scheduled to mature in June 2022 and the 2017 Term B Loan Facility is scheduled to mature in June 2024. The principal amount of the term B loans under the 2017 Term B Loan Facility (“term B loan”) amortize in equal quarterly installments in an aggregate annual amount of (i) 1.00% of the original principal amount of such term B loans through December 31, 2019 and (ii) 2.00% thereafter. The maturity dates under the 2017 Revolving Credit Facility and the 2017 Term Loan Facility are subject to extension with lender consent according to the terms of the 2017 Credit Agreement. The 2017 Credit Agreement includes provisions requiring ARH to offer to prepay term B loans in an amount equal to (i) the net cash proceeds above certain thresholds received from (a) asset sales and (b) casualty events resulting in the receipt of insurance proceeds, subject to customary provisions for the reinvestment of such proceeds, (ii) the net cash proceeds from the incurrence of debt not otherwise permitted under the 2017 Credit Agreement, and (iii) a percentage of consolidated excess cash flow retained in the business from the preceding fiscal year minus voluntary prepayments. For the period from April 26, 2019 until the date on which ARH has delivered the consolidated financial statements for the fiscal quarter ended March 31, 2019 and no default under the 2017 Credit Agreement is continuing (the “Covenant Reversion Date”), the term B loans under the 2017 Term B Loan Facility bear interest at a rate equal to, at ARH’s option, either (a) an alternate base rate equal to the higher of (1) the prime rate in effect on such day, (2) the federal funds effective rate plus 0.50% or (3) the Eurodollar rate applicable for a one-month interest period plus 1.00% (collectively, the “ABR Rate”), plus an applicable margin of 4.50% (increased from 2.25% prior to the Amendment), or (b) LIBOR, adjusted for changes in Eurodollar reserves (“Eurodollar Rate”), plus an applicable margin of 5.50% (increased from 3.25% prior to the Amendment). From and after the Covenant Reversion Date, the applicable margin on term B loans will be 4.00% for ABR Rate loans and 5.00% for Eurodollar rate loans. For the period from April 26, 2019 until the Covenant Reversion Date, outstanding loans under the 2017 Revolving Credit Facility bear interest at a rate equal to, at ARH’s option, either (a) the ABR Rate, plus an applicable margin of 4.25% , or (b) the Eurodollar Rate, plus an applicable margin of 5.25% , instead of pricing each such margin off a grid based upon the consolidated net leverage ratio of ARH and its restricted subsidiaries. From and after the Covenant Reversion Date, any outstanding loans under the revolving credit facility will bear interest at a rate equal to, at ARH’s option, either the ABR Rate or the Eurodollar Rate, plus, in each case, an applicable margin priced off a grid based upon the consolidated net leverage ratio of ARH and its restricted subsidiaries, which margin is 1.75% higher than the applicable margin prior to the Amendment. There were $5.5 million of borrowings outstanding under the 2017 Revolving Credit Facility as of December 31, 2018. Prior to the Amendment, the commitment fee applicable to undrawn revolving commitments under the 2017 Revolving Credit Facility was priced off a grid based upon the consolidated net leverage ratio of ARH and its restricted subsidiaries and, as of December 31, 2018, was 0.50% . For the period from April 26, 2019 until the Covenant Reversion Date, the commitment fee applicable to undrawn revolving commitments under the 2017 Revolving Credit Facility will be 0.50% without regard to the consolidated net leverage ratio. In addition, until the Covenant Reversion Date, ARH will not be permitted to incur revolving credit loans or swing line loans or have letters of credit issued if, after giving effect to the incurrence or issuance, the Company's cash and cash equivalents would exceed $75,000 . The 2017 Credit Agreement contains customary events of default, the occurrence which would permit the lenders to accelerate payment of the full amounts outstanding. Additionally, the 2017 Credit Agreement contains customary representations and warranties, affirmative covenants and negative covenants, including restrictive financial and operating covenants. As a result of the Restatement and related matters, as of December 31, 2018, ARH was not in compliance with all of these covenants, which non-compliance was waived for the period specified in the Amendment. The 2017 Credit Agreement includes a springing maximum consolidated net leverage ratio financial covenant of 6.00 :1.00 for the benefit of the lenders under the 2017 Revolving Credit Facility (the “Revolver Financial Covenant”) and, following the Amendment a maximum consolidated net leverage ratio maintenance financial covenant of 7.00 :1.00 for the benefit of the lenders under both the 2017 Revolving Credit Facility and the 2017 Term B Loan Facility. As of December 31, 2018, we were in compliance with the applicable consolidated net leverage ratio. In addition, the Amendment added a new event of default in the event it is determined that ARH failed to satisfy the maximum consolidated net leverage ratio at the time of borrowing under the 2017 Revolving Credit Facility or when required on or after the last day of the fiscal quarter ended December 31, 2018 or the fiscal quarter ended March 31, 2019. The Amendment also waived any default or events of default that may have resulted from ARH underpaying any interest payments or letter of credit fees based on the application of a lower applicable rate due to the delivery, prior to the effective date of the Amendment, of inaccurate financial statements if such inaccuracy arose out of the Inaccurate Matters (as defined below). However, ARH will be required to pay any accrued interest and letter of credit fees that are ultimately determined to have been payable but for such lower applicable rate. The Amendment waived inaccuracies of certain representations and warranties previously made to the extent that the inaccuracies were a result of (i) inaccuracies or errors in financial reporting, accounting and related metrics described in the Current Report on Form 8-K filed by ARAH with the Securities and Exchange Commission on March 27, 2019 (the “March 27 Form 8-K”) or otherwise identified pursuant to, or as a result of, the review of the audit committee of the board of directors of ARAH described in the March 27 Form 8-K, and (ii) any weaknesses in internal control over financial reporting related to the foregoing (together, the “Inaccurate Matters”). The obligations of ARH under the 2017 Credit Agreement are guaranteed by ARHIC and all of its existing and future wholly owned domestic subsidiaries (collectively, the “Guarantors”) and secured by a pledge of all of ARH’s capital stock and substantially all of the assets of ARH and the Guarantors, including their respective interests in their joint ventures. The Company’s clinic-level debt includes third-party term loans and lines of credit, as well as the Assigned Clinic Loans. Due to the factors that led to the Restatement and the Company’s material weaknesses, the Company failed to, among other things, timely deliver certain financial statements to these lenders as required, resulting in defaults under the applicable loan documents. The Company obtained individual waivers or forbearances from substantially all of its third-party clinic lenders, and continue to seek waivers or forbearances for the Assigned Clinic Loans and from the remaining lenders. The total balance of clinic-level debt as of December 31, 2018 for which the Company has not obtained waivers through the date of issuance of these consolidated financial statements amounts to approximately $4.2 million of which the long-term portion of the balance at both March 31, 2019 and June 30, 2019 will be reclassified to current portion of long-term debt. Subsequent Amendment of Interest Rate Swap Agreement and Interest Rate Cap Agreements Effective May 7, 2019, the Company obtained an amendment and waiver related to the 2017 Interest Rate Swap Agreement. The amendment waived any defaults or potential default under the Swap Agreement arising from ARH’s prior delivery of certain inaccurate financial statements, any associated breach of representations and warranties regarding the accuracy of such financial statements, and the delay in the Company’s filing of its Form 10-K. Under terms of the Amendment, any such defaults or potential defaults are waived until the earlier of (i) September 9, 2019 or (ii) such date as ARH has provided the lenders with the Company’s Form 10-K. Effective May 16, 2019, the Company obtained an amendment and waiver related to the 2017 Interest Rate Cap Agreements. The amendment waived any defaults or potential default under the Cap Agreements arising from ARH’s prior delivery of certain inaccurate financial statements, any associated breach of representations and warranties regarding the accuracy of such financial statements, and the delay in the Company’s filing of its Form 10-K. Under terms of the Amendment, any such defaults or potential defaults are waived until the earlier of (i) September 9, 2019 or (ii) such date as ARH has provided the lenders with the Company’s Form 10-K.

Leases

Leases	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Leases	Leases Substantially all of the Company’s facilities are leased under noncancelable operating leases expiring in various years through 2033. Most lease agreements cover periods from five to fifteen years and contain renewal options of five to ten years at the fair rental value at the time of renewal. Certain leases are subject to rent holidays and/or escalation clauses. The Company expenses rent using the straight‑line method over the initial lease term starting from date of possession. Tenant allowances received from lessors are capitalized and amortized over the initial term of the lease. Rent expense under operating leases was $30,843 in 2018 , $28,546 in 2017 and $25,346 in 2016 . Total amortization expenses for assets purchased under capital leases were $213 in 2018. There were no capital leases in 2017 or 2016. The Company leases certain facilities from noncontrolling interest members or entities under the control of noncontrolling interest members. Rent expense under these lease arrangements was approximately $10,778 , $10,160 and $8,238 in 2018 , 2017 and 2016 , respectively. The Company subleases space at certain of these facilities to the noncontrolling interest members. Rental income under these sub‑lease arrangements, which extends to 2033, amounted to $963 , $853 and $813 in 2018 , 2017 and 2016 , respectively. Future receipts of $6,581 due from these related parties are included in sublease receipts presented below. The Company subleases space in certain of its facilities to nephrologist partners at market values under non‑cancelable operating leases expiring in various years through 2032. Rental income under these subleases was $1,709 in 2018 , $1,515 in 2017 and $1,439 in 2016 . Future minimum lease payments under noncancelable operating leases, net of sublease receipts and capital leases as of December 31, 2018 , are as follows: Year Ended December 31, Operating Leases Less: Sublease Receipts Net Operating Leases Capital Leases 2019 $ 31,311 $ 1,537 $ 29,774 $ 876 2020 29,608 1,551 28,057 930 2021 27,597 1,572 26,025 940 2022 25,132 1,592 23,540 950 2023 20,363 1,117 19,246 963 Thereafter 61,085 3,175 57,910 6,286 Total minimum lease payments $ 195,096 $ 10,544 $ 184,552 $ 10,945 Less: amount representing interest 4,239 Present value of net minimum capital lease payments $ 6,706 Less: current installments of obligations under capital leases 302 Long-term capital lease obligation $ 6,404 The Company adopted ASU 2016-02 effective January 1, 2019. See “ Note 2 - Summary of Significant Accounting Policies ” for additional information.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision for income taxes consisted of the following for the years ended December 31 : 2018 2017 2016 (restated) (restated) Current: Federal $ (112 ) $ (2,000 ) $ 17,432 State 657 173 3,617 $ 545 $ (1,827 ) $ 21,049 Deferred: Federal $ 1,348 $ 9,435 $ (15,873 ) State 1,003 1,863 (2,697 ) $ 2,351 $ 11,298 $ (18,570 ) Total provision for income taxes $ 2,896 $ 9,471 $ 2,479 The significant components of deferred tax assets and liabilities are as follows at December 31 : 2018 2017 2016 (restated) (restated) Net operating loss and contribution carryforwards $ 5,542 $ 5,541 $ 7,092 Legal settlement (Note 23) 5,065 — — Accrued expenses 1,484 1,115 1,519 Stock-based compensation 9,417 9,708 16,568 Interest limitation 2,189 — — Other 165 165 250 Interest rate swap — 379 66 Deferred tax assets: 23,862 16,908 25,495 Valuation allowance (12,420 ) (5,414 ) — Total deferred tax assets 11,442 11,494 25,495 Investment in joint ventures (9,784 ) (7,254 ) (8,039 ) Goodwill and intangible amortization (3,400 ) (3,331 ) (4,943 ) Depreciation (1,378 ) (1,293 ) (2,054 ) Other (49 ) (38 ) (110 ) Total deferred tax liabilities (14,611 ) (11,916 ) (15,146 ) Net deferred tax (liabilities) assets $ (3,169 ) $ (422 ) $ 10,349 As of December 31, 2018 , the Company has $3,410 in state loss carryforwards which expire at various dates ending 2033 and $20,510 in charitable contribution carryforwards which expire at various dates ending in 2023. As of December 31, 2018, the Company has recorded a valuation allowance of $12,420 against all federal and state tax assets because it has determined that it is not more likely than not that the deferred tax assets will be realized. The current year change in the valuation allowance of $7,006 relates primarily to the following: increase related to current year charitable contributions of $1,042 , a decrease of $1,041 related to the expiration of charitable contribution benefits and a $7,005 increase related to the valuation allowance on all other deferred tax assets. On December 22, 2017, the United States enacted tax reform legislation commonly known as the Tax Cuts and Jobs Act (the “2017 Tax Act”), resulting in significant modifications to existing law. The Company has completed the accounting for the effects of the 2017 Tax Act during the year ended December 31, 2018. The Company recorded a net income tax of $2,700 during the fourth quarter of 2017 as a result of the 2017 Tax Act. The income tax expense included in the accompanying consolidated statements of operations principally relates to the Company’s proportionate share of the pre‑tax income from its ownership in joint venture subsidiaries. A reconciliation of the federal statutory rate to the Company’s effective tax rate is as follows for the years ended December 31 : 2018 2017 2016 (restated) (restated) Income tax provision at federal statutory rate 21 % 35 % 35 % Increase (decrease) in tax resulting from: State taxes, net of federal benefit (2.9 )% 0.6 % 0.9 % Noncontrolling interests in passthrough entities (44.0 )% (32.3 )% (33.4 )% Valuation allowance 33.0 % 8.7 % — % Other permanent items, net 4.8 % 2.0 % (0.1 )% Effective income tax rate 11.9 % 14.0 % 2.4 % The Company and its subsidiaries file U.S. federal income tax returns and various state returns. The Company is no longer subject to U.S. federal, state and local examinations by tax authorities for years before 2012. The Company is currently under audit by the state of Louisiana for the 2013-2015 tax years and the District of Columbia for the tax years 2013-2017 as of December 31, 2018 . The following table summarizes the gross amounts of unrecognized tax benefits without regard to reduction in tax liabilities or additions to deferred tax assets and liabilities if such unrecognized tax benefits were settled: 2018 2017 2016 January 1 $ 21,077 $ 25,062 $ 15,833 Increase due to current year tax positions — — 9,229 Decrease due to prior year tax positions (4,109 ) (3,985 ) — December 31 $ 16,968 $ 21,077 $ 25,062 The total amount of unrecognized tax benefits that, if recognized, would impact the effective tax rate was $6,633 , $9,245 , and $11,020 as of December 31, 2018 , 2017, and 2016, inclusive of $2,511 , $1,353 , and $474 , respectively, of interest related to uncertain tax positions and are included in Accrued expenses and other current liabilities on our consolidated balance sheets. The Company believes that it is reasonably possible that the recorded amount of gross unrecognized tax benefits as of December 31, 2018 may decrease within twelve months of the reporting date as a result of the filing of Forms 3115 in the third quarter of 2019.

Loss Per Share

Loss Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Loss Per Share	Loss Per Share Basic loss per share is computed by dividing net income (loss) attributable to American Renal Associates Holdings, Inc., net of the change in the difference between the redemption value and estimated fair value for accounting purposes of related noncontrolling interest put provisions, by the weighted-average number of common shares outstanding during the applicable period, less unvested restricted stock. Diluted loss per share is computed using the weighted-average number of common shares outstanding during the applicable period, plus the dilutive effect of outstanding options, using the treasury stock method and the average market price of the Company’s common stock during the applicable period. Certain shares related to some of the Company’s outstanding stock options were excluded from the computation of diluted earnings per share because they were anti-dilutive in the periods presented, but could be dilutive in the future. Year ended December 31, 2018 2017 2016 (restated) (restated) Basic and Diluted Net (loss) income attributable to American Renal Associates Holdings, Inc. $ (28,767 ) $ (4,597 ) $ 3,146 Change in the difference between the redemption values and estimated fair values for accounting purposes of the related noncontrolling interests (2,566 ) (11,503 ) (10,067 ) Net loss attributable to common shareholders (31,333 ) (16,100 ) (6,921 ) Weighted‑average common shares outstanding 31,965,844 31,081,824 28,118,673 Weighted‑average common shares outstanding, assuming dilution 31,965,844 31,081,824 28,118,673 Loss per share, basic and diluted $ (0.98 ) $ (0.52 ) $ (0.25 ) Outstanding options excluded as impact would be antidilutive 3,442,048 1,894,340 572,097

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The majority of the Company’s stock‑based compensation arrangements consist of options having a ten -year term and either vest over a three or five year vesting schedule (service‑based), on the occurrence of an event (market-based) or upon the achievement of certain performance conditions (performance‑based). The Company’s stock‑based compensation awards are measured at their estimated grant‑date fair value. For the performance or service‑based stock awards, compensation expense is recognized on the straight‑line method over their requisite service periods, and is adjusted each period for actual forfeitures. For market and performance based awards, the Company defers all stock‑based compensation until it is probable that the event, as defined, will occur. The Company grants options that allow for the settlement of vested stock options on a net share basis (“net settled stock options”), under certain circumstances, instead of settlement with a cash payment. With net settled stock options, the employee does not surrender any cash or shares upon exercise. Rather, the Company withholds the number of shares to cover the option exercise price and the minimum statutory tax withholding obligations from the shares that would otherwise be issued upon exercise. The settlement of vested stock options on a net share basis results in fewer shares issued by the Company. Share‑Based Compensation Plans: (a) American Renal Holdings Inc. 2005 Equity Incentive Plan In December 2005, the Company established the American Renal Holdings Inc. 2005 Equity Incentive Plan (the “2005 Plan”), under which common stock were reserved for issuance to employees, directors, and consultants. Options granted under the 2005 Plan may be incentive stock options or nonstatutory stock options. In response to the May 2010 acquisition of the Company by certain affiliates of Centerbridge Capital Partners, L.P. and certain members of management, options granted under the 2005 Plan became exercisable into American Renal Associates Holdings, Inc. As of December 31, 2018 , options to purchase an aggregate of 11,120 shares of common stock were outstanding under the 2005 Plan. (b) American Renal Associates Holdings, Inc. 2010 Stock Incentive Plan In May 2010, the Company adopted the American Renal Associates Holdings, Inc. 2010 Stock Incentive Plan (the “2010 Plan”) under which 3,606,251 shares of the Company’s common stock were reserved for issuance to the Company’s employees, directors and consultants. In March 2014, the Company’s Board of Directors approved authorizing the issuance of an additional 1,627,258 shares under the plan. Options granted under the 2010 Plan must be nonstatutory stock options. Stock appreciation rights may also be granted under the 2010 Plan. As of December 31, 2018 , options to purchase an aggregate of 3,859,143 shares of common stock were outstanding under the 2010 Plan. (c) American Renal Associates Holdings, Inc. 2011 Stock Option Plan for Nonemployee Directors In January 2011, the Company adopted the American Renal Associates Holdings, Inc. 2011 Stock Option Plan for Nonemployee Directors (the “2011 Director’s Plan”) under which 100,000 shares of the Company’s common stock were reserved for issuance to the Company’s directors and consultants. Options granted under the 2011 Director’s Plan must be nonstatutory stock options. Stock appreciation rights may also be granted under the 2011 Director’s Plan. As of December 31, 2018 , options to purchase an aggregate of 34,350 shares of common stock were outstanding under the 2011 Director’s Plan. (d) American Renal Associates Holdings, Inc. 2016 Omnibus Plan On April 7, 2016, the Company approved the 2016 Omnibus Incentive Plan (the “2016 Plan”). The 2016 Plan authorized the Company to issue options and other awards to directors, officers, employees, consultants and advisors to purchase up to a total of 4,000,000 shares of common stock. As of December 31, 2018 , options to purchase an aggregate of 1,106,578 shares of common stock, and 441,063 unvested restricted stock awards, were outstanding under the 2016 Plan. Shares Reserved As of December 31, 2018 , there were 2,056,620 shares remaining for issuance for future equity grants under the Company’s 2016 Plan. There were no shares available for future equity grants under the 2005 Plan, 2010 Plan and 2011 Director’s Plan. Equity Grants, Assumptions and Activity The following table presents the stock‑based compensation expense and related income tax benefit included in the Company’s consolidated statements of operations for the years ended December 31 : 2018 2017 2016 Patient care costs $ 714 $ 2,773 $ 5,720 General and administrative 5,007 13,099 34,578 Total stock‑based compensation $ 5,721 $ 15,872 $ 40,298 Income tax benefit $ 1,493 $ 6,349 $ 16,119 Stock Options The Company estimates the grant-date fair value of stock options by using a Monte Carlo simulation‑based approach for the portion of the option that contains both a market and performance condition and the Black‑Scholes valuation model for the portion of the option that contains a performance or service‑based condition. Key inputs used to estimate the fair value of stock options include the exercise price of the award, the expected term of the option, the expected volatility of the Company’s common stock over the option’s expected terms, the risk‑free interest rate over the option’s expected term and the Company’s expected annual dividend yield. The weighted‑average assumptions used in the option valuation models for awards granted in 2018 , 2017 and 2016 are as follows. 2018 2017 2016 Expected volatility(1) 30 - 35% 30 - 35% 25 % Expected term in years(2) 6.0 6.0 6.0 - 6.5 Risk-free interest rate(3) 2.74 - 2.99% 1.92 - 2.26% 1.20 - 1.58% Expected annual dividend yield(4) — % — % — % Weighted-average grant-date fair value $ 7.14 $ 5.52 $ 6.24 (1) Since the Company does not have sufficient history as a public company and does not have sufficient trading history for its common stock, the expected volatility was largely estimated based on the historical equity volatility of common stock of comparable publicly traded entities over a period equal to the expected term of the stock option grants. For each of the comparable publicly traded entities, the historical equity volatility and the capital structure of the entity were used to calculate the implied stock volatility. The average implied stock volatility of the comparable publicly traded entities was then used to calculate a relevered equity volatility for the Company based on the Company’s own capital structure. In the first quarter of 2018, the Company utilized the relevered equity volatility based on the comparable publicly traded entities for the Company and beginning in the second quarter of 2018, the Company began weighting in its own historical equity volatility to arrive at the concluded weighted-average equity volatility for the option valuation model. The comparable entities from the healthcare sector were chosen based on area of specialty. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of the Company's own stock price becomes available. (2) Expected term of 6.0 years for a service‑based option is based on the “short‑cut method” as prescribed by Securities and Exchange Commission’s Staff Accounting Bulletin No. 110. (3) The risk‑free interest rate is based on the yield of zero‑coupon U.S. Treasury securities for a period that is commensurate with the expected option term at the time of grant. (4) Expected dividend yield is based on management’s expectations. The following table summarizes the combined stock option activity under the Company’s stock option plans for the year ended December 31, 2018 : Number of Shares Weighted - Weighted - average Aggregate Options outstanding as of January 1, 2018 5,280,261 $ 11.79 Granted 296,286 19.32 Exercised (348,442 ) 5.17 Forfeited/Cancelled (216,914 ) 16.50 Options outstanding as of December 31, 2018 5,011,191 $ 12.38 4.99 $ 17,056 Vested and expected to vest as of December 31, 2018 5,011,191 $ 12.38 4.99 $ 17,056 Exercisable as of December 31, 2018 3,172,792 $ 8.29 3.98 $ 17,056 The aggregate intrinsic value of stock options exercised (i.e., the difference between the market price at exercise and the price paid by the employee at exercise) in 2018 , 2017 and 2016 was $4,825 , $10,974 and $1,299 , respectively. As of December 31, 2018 , the Company had approximately $6,178 of unrecognized compensation costs related to unvested share‑based compensation arrangements of which $408 is attributable to share‑based awards with market and performance conditions and $5,771 is attributable to time‑based vesting. The compensation cost associated with unvested awards is expected to be recognized as expense over a weighted‑average period of approximately 3.4 years. Restricted Stock Awards Employees and directors are eligible to receive grants of restricted stock, which entitle the holder to shares of common stock as the awards vest. The Company determines stock-based compensation expense using the fair value method. The fair value of restricted stock is equal to the closing sale price of the Company’s common stock on the date of grant. In March 2018, the Company granted approximately 95,000 performance-based restricted stock awards to certain executives, with a weighted average grant date fair value per share of $22.33 . These awards will vest at the end of the three -year service period and the quantity of awards that vest is dependent upon the Company's achievement of defined performance metrics. The Company has determined that the performance conditions for these awards are probable of achievement as of December 31, 2018 . As of December 31, 2018 , a total of 441,063 shares of restricted stock were unvested and outstanding, which results in unamortized stock-based compensation of $4,929 to be recognized as stock-based compensation expense over the remaining weighted-average vesting period of 1.3 years. A summary of restricted stock award activity is as follows: Number of Shares Weighted - average grant date fair value Unvested as of January 1, 2018 252,307 $ 16.70 Granted 359,691 22.18 Vested (100,553 ) 16.91 Forfeited/Cancelled (70,382 ) 19.48 Unvested as of December 31, 2018 441,063 $ 20.68 The total fair value of restricted stock vested during the years ended December 31, 2018 and 2017 was approximately $1,701 and $440 , respectively. There was no vested restricted stock during the years ended December 31, 2016 . Stock Option Modification In connection with the dividends paid at the time of the IPO, equitable adjustments are required by the terms of some of the Company's equity incentive plans and for other plans were modified at the discretion of the Company's Board of Directors. See “ Note 4 - Initial Public Offering ”.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Term Loan Holdings The Company administers and manages the Assigned Clinic Loans as servicer pursuant to the terms of a loan servicing agreement as entered into between the Company and Term Loan Holdings. The Company is paid a quarterly fee for its services based on its reasonable costs and expenses, plus a specified percentage of such costs and expenses, which may be adjusted annually based on negotiations between the Company and Term Loan Holdings. The fee charged for the year ended December 31, 2018 is immaterial. See “ Note 4 - Initial Public Offering ” and “ Note 15 - Debt .” Due from Related Party As described in “ Note 16 - Leases ,” the Company subleases space in its facilities to certain nephrologist partners. In connection with certain such subleases, the Company loaned a total initial amount of $2,445 for various facility buildouts. The loans had an interest rate of 6% with maturities ranging from March 2026 through September 2033. Fixed principal and interest payments with respect to such loans are payable monthly. As of December 31, 2018 , the remaining balance to be paid to the Company was $2,224 , which is included in Prepaid expenses and other current assets on the consolidated balance sheet. Transactions with Executive Officer The Company licenses software relating to electronic medical record solutions from Kinetic Decision Solutions LLC (“Kinetic”) which is owned 51% by an executive officer of the Company, and 2.5% by his spouse. The executive is also Co-Founder, Chief Executive Officer and Managing Partner of Kinetic. Under the terms of this arrangement, the Company paid to Kinetic $318 , $310 , and $344 during the year ended December 31, 2018 , 2017 , and 2016 respectively. The executive officer and his spouse, through a trust in which the executive officer's spouse is trustee and beneficiary, are partners in certain of the Company's clinic JVs. The clinics in which the executive officer and/or his spousal trust have an ownership interest all receive intercompany revolving loans made through the Company, and have a portion of their financing in the form of term loans held by Term Loan Holdings. As of December 31, 2018 , 2017 , and 2016 , the aggregate principal amount outstanding of the intercompany revolving loans and assigned clinic loans made to the Company's joint ventures in which the executive officer and/or his spousal trust have an ownership interest was approximately $4,065 , $6,027 , and $7,213 , respectively. As of December 31, 2018 , such loans had maturities ranging from February 2019 to August 2024, with a weighted average maturity of approximately 3.4 years (May 2022), and interest rates ranging from 3.31% to 6.30% , with a weighted average interest rate of 4.8% . Fixed principal and interest payments with respect to such loans are payable monthly. Each loan is secured by the assets of the applicable joint venture clinic and is, and will continue to be, guaranteed by the Company and the executive officer and/or his spousal trust in proportion to each party’s ownership interests in the applicable joint venture. Based on their proportionate ownership interest in such joint ventures, the executive officer and/or his spousal trust guaranteed approximately $692 of such outstanding loans as of December 31, 2018 .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company had obligations under contracts related to the construction of clinics totaling $4,367 as of December 31, 2018 which are expected to be paid in 2019 . The Company has aggregate additional purchase obligations of $139,625 for minimum purchase commitments over a period of five years under its agreements with certain suppliers. In the event of a shortfall, the Company is required to pay in cash a portion or all of the amount of such shortfall or may, under certain circumstances, be subject to a price increase or other fee. The Company entered into an additional purchase agreement in March 2019 with a supplier for an amount of approximately $105,000 in years 2019 through 2022. Income Tax Receivable Agreement As described in “ Note 4 - Initial Public Offering ” and “ Note 8 - Fair Value Measurements ,” the Company is a party to the TRA under which it is contractually committed to pay its pre-IPO stockholders on a pro rata basis 85% of the amount of cash savings, if any, in U.S. federal, state and local income tax that it actually realizes (or are deemed to realize in the case of an early termination payment by the Company, or a change of control, as discussed below) as a result of any option deductions (as defined in the TRA). The actual amount and timing of any payments under the TRA will vary depending upon a number of factors, including the amount and timing of taxable income the Company generates in the future, changes in the income tax rate, whether and when any relevant stock options, as defined in the TRA, are exercised and the value of the Company's common stock at the time of such exercise. Regulatory The healthcare industry is subject to numerous laws and regulations of federal, state, and local governments. Government activity has increased with respect to investigations and allegations concerning possible violations by healthcare providers of fraud and abuse statutes and regulations, which could result in the imposition of significant fines and penalties, as well as significant repayments for patient services previously billed. Compliance with such laws and regulations are subject to government review and interpretations, as well as regulatory actions unknown or unasserted at this time. In addition, see “Note 23 - Certain Legal and Other Matters” below.

Certain Legal Matters and Other

Certain Legal Matters and Other Matters	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Certain Legal Matters and Other Matters	Certain Legal and Other Matters The following is a description of certain lawsuits, claims, governmental investigations and audits and other legal proceedings to which the Company is subject. Government Inquiries and Investigations On January 3, 2017, the Company received a subpoena from the United States Attorney’s Office, District of Massachusetts, requesting certain information relating to the Company’s payments and other interactions with the American Kidney Fund and any efforts to educate patients qualified or enrolled in Medicare or Medicaid about enrollment in ACA-compliant individual marketplace plans, among other related matters under applicable healthcare laws. The Company cooperated fully with the government. The Company believes that this investigation related to a complaint, unsealed on August 1, 2019 in the U.S. District Court for the District of Massachusetts, that named certain of its competitors, the AKF and certain unidentified parties as defendants. The complaint alleges violations of the federal False Claims Act and various state false claims acts. The Department of Justice elected not to intervene in the matter. While the Company was not identified as a defendant in the matter, it can make no assurance that it will not be named as one of the unidentified defendant parties. In October 2018, the Staff of the SEC requested that the Company voluntarily provide documents and information relating to certain revenue recognition, collections and related matters. On March 27, 2019, the Company filed a Current Report on Form 8-K (the “March 27 Form 8-K”) that described, among other things, certain preliminary findings arising from the review being conducted by the Audit Committee of the Board, which commenced following receipt of the SEC request. On March 28, 2019, the Company received a subpoena from the Staff of the SEC, which reiterated the SEC’s prior request and required the production of additional documents and information relating to the matters disclosed in the March 27 Form 8-K and related matters. On June 19, 2019, the Company received an additional subpoena from the Staff of the SEC, which required the production of additional related documents and information. The Company may receive additional related subpoenas or other requests for documents and information from the Staff. The Company has cooperated fully with this investigation and will continue to do so. Shareholder and Derivative Claims On March 28, 2019 and April 19, 2019, putative shareholder class action complaints were filed in the United States District Court for the District of New Jersey against the Company and certain of its current and former executive officers. Both complaints allege violations of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, and Rule 10b-5 thereunder related to the matters disclosed in the March 27 Form 8-K and certain prior filings. The complaints seek unspecified damages on behalf of the individuals or entities that purchased or otherwise acquired ARA’s securities from August 10, 2016 to March 27, 2019. On July 3, 2019, the complaints were consolidated and a lead plaintiff was appointed for the putative shareholder class action complaint, captioned Ali Vandevar, et al. v. American Renal Associates Holdings Inc., et al. , No. 19-09074-ES-MA. The Company, the Board, and its current and former executive officers could become subject to additional litigation relating to these matters. The Company intends to vigorously defend itself against these claims. On July 25, 2019, a derivative lawsuit, Luke Johnson v. Joseph A. Carlucci, et al. , 2:19-CV-15812-JMV-JBC, was filed, purportedly on behalf of the Company, in the United States District Court for the District of New Jersey against the members of the Company’s board of directors and certain of its current and former executive officers. The lawsuit asserts claims for violations of Section 14(a) of the Exchange Act, breach of fiduciary duties, unjust enrichment and waste of corporate assets based on, among other things, the Restatement and the related material weaknesses in the Company’s internal control over financial reporting, alleged misstatements and omissions in the Company’s 2017 and 2018 proxy statements, compensation paid to the individual defendants and the costs incurred in connection with the Restatement process. The lawsuit seeks, among other things, recovery of damages sustained by the Company as a result of the individual defendants’ alleged misconduct, a direction to the Company to hold an annual meeting of stockholders and reforms to the Company’s corporate governance and internal procedures. The complaint also seeks restitution and costs and attorney’s fees. Other From time to time, the Company is subject to various legal actions and proceedings involving claims incidental to the conduct of its business, including contractual disputes and professional and general liability claims, as well as audits and investigations by various government entities, in the ordinary course of business. Based on information currently available, established reserves, available insurance coverage and other resources, the Company does not believe that the outcomes of any such pending actions, proceedings or investigations in the ordinary course of business, are likely to be, individually or in the aggregate, material to its business, financial condition, results of operations or cash flows. However, legal actions and proceedings are subject to inherent uncertainties, and it is possible that the ultimate resolution of such matters, if unfavorable, may be materially adverse to the Company's business, financial condition, results of operations or cash flows. Although the Company is not currently subject to any formal regulatory investigations or proceedings other than those described herein, there is no assurance that any such investigations or proceedings will not be commenced by any U.S. federal or state healthcare or other regulatory agencies. In addition, the Company may in the future be subject to additional inquiries, investigations, litigation or other proceedings or actions, regulatory or otherwise, arising in relation to the matters described above and related litigation and investigative matters. An unfavorable outcome of any such litigation or regulatory proceeding or action could have a material adverse effect on the Company's business, financial condition and results of operations. The Company also records in Certain legal and other matters, legal fees and other expenses relating to matters that it believes do not reflect its core business operations. Resolved Matters The wholly owned operating subsidiary of ARA, American Renal Associates LLC (“ARA OpCo”), and its subsidiary, American Renal Management LLC (“ARM”), were defendants in lawsuits filed by affiliates of UnitedHealth Group Incorporated (“United”) in the United States District Court for the Southern District of Florida (Case Number 9:16-cv-81180-KAM), filed July 1, 2016, and the United States District Court for the District of Massachusetts (Case Number 1:18-cv-10622-ADB), filed March 30, 2018. On July 2, 2018, ARA OpCo and ARM executed a binding Settlement Term Sheet with the plaintiffs with respect to a settlement to resolve all ongoing litigation between the Company and United, and on August 1, 2018, the parties entered into a final settlement agreement (the “Settlement Agreement”) on substantially the same terms as provided in the Settlement Term Sheet. The Settlement Agreement included a release of all claims arising from or related to the above-referenced litigations that were asserted or that could have been asserted against the Company or against the nephrologists or other healthcare providers who have entered into joint venture arrangements or medical directorships with the Company (the “Joint Venture Providers”) and the joint venture entities without any admission of liability or wrongdoing. Pursuant to the Settlement Agreement, the Company will make total settlement payments of $32,000 , inclusive of administrative fees and fees for plaintiffs’ counsel, in five installments, with an initial present value of $29,614 , which is included in Certain legal and other matters in the Statement of Operations during the year ended December 31, 2018, and a remaining present value of $19,614 . As of December 31, 2018, $7,641 is classified as Accrued expenses and other current liabilities and $11,973 is classified in Other long-term liabilities. The Company paid the first installment of $10,000 on August 1, 2018 and the second installment of $8,000 on August 1, 2019 and expects to pay $7,000 on August 1, 2020, $3,500 on August 1, 2021 and $3,500 on August 1, 2022. The Company also agreed to share certain information with United and to follow certain procedures with respect to patients covered by United. Subject to the mutual releases provided in the Settlement Agreement, United also agreed to renew, reinstate, and/or not to terminate the network agreements for any Joint Venture Providers whose network agreements United terminated or chose not to renew from August 1, 2017 through the date of the Settlement Agreement. The Settlement Agreement included customary terms and conditions. In connection with the Settlement Agreement, the Company also entered into a three -year national network agreement with United on August 1, 2018 that provides for specified reimbursement rates for patients covered by Medicare Advantage, Medicaid HMO and commercial insurance products over the term of the agreement. The in-network agreement went into effect on September 1, 2018. On July 26, 2016, the Staff of the SEC sent a letter to the Company stating that it was conducting an inquiry and requesting that the Company provide certain documents and information relating to the subject matter covered by the United complaint described above. On April 28, 2017, the Company was notified by the SEC Staff that the SEC had concluded its investigation and, based on the information it had as of that date, did not intend to recommend an enforcement action against the Company. On August 31, 2016 and September 2, 2016, putative shareholder class action complaints were filed in the United States District Court for the Southern District of New York and the United States District Court for the District of Massachusetts, respectively, against the Company and certain officers and directors of the Company. On October 26, 2016, the complaint filed in the Southern District of New York was voluntarily dismissed by the plaintiff without prejudice. On June 15, 2018, the United States District Court for the District of Massachusetts approved a Stipulation of Settlement, entered into between the Company and Lead Plaintiff on January 30, 2018 in the matter captioned Esposito, et al. v. American Renal Associates Holdings, Inc., et al., Case No. 16-cv-11797 (ADB). The Stipulation of Settlement provided for a total settlement payment of $4,000 , inclusive of administrative fees and fees for the lead plaintiff’s counsel. Substantially all of the settlement was funded by insurance proceeds. The settlement released all claims asserted against the Company and the other named defendants in the action without any liability or wrongdoing attributed to them. On October 25, 2017, Stephen Bushansky, a shareholder, filed a derivative lawsuit purportedly on behalf of the Company against the members of its board of directors. The lawsuit was filed in the United States District Court for the District of Massachusetts. On May 31, 2018, the United States District Court for the District of Massachusetts approved a settlement agreement, entered into between the Company and Steven Bushansky on March 29, 2018 in the matter captioned Stephen Bushansky, Derivatively on Behalf of American Renal Associates Holdings, Inc. v. Joseph A. Carlucci, et. al., Case No. 17-cv-12091 (ADB). The settlement agreement provided for, among other things, a settlement payment of $350 , inclusive of attorney’s fees, and certain corporate governance changes. The payment was made by the Company’s insurer. The settlement resolved the claims asserted against all defendants in the action without any liability or wrongdoing attributed to them. CMS Request for Information On August 18, 2016, the Centers for Medicare and Medicaid Services (“CMS”) issued a request for information seeking public comment on the concerns that some healthcare providers and provider-affiliated organizations may be steering patients eligible for, or receiving, Medicare and/or Medicaid benefits into ACA-compliant individual marketplace plans, including health insurance marketplace plans. The request for information also sought comment about certain charities that provide assistance to patients seeking private insurance coverage. CMS also sent letters to all Medicare-enrolled dialysis facilities and centers informing them of this request for information. The Company provided a response to the CMS request for information.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit Plan In 2018 , the Company sponsored a 401(k) defined contribution retirement plan for qualifying employees. The Company made no contributions to the plan in 2018 , 2017 and 2016 .

Concentrations

Concentrations	12 Months Ended
	Dec. 31, 2018
Risks and Uncertainties [Abstract]
Concentrations	Concentrations The Company holds cash at several major financial institutions, which are insured by the Federal Deposit Insurance Corporation up to $250 . The Company maintains balances in excess of these limits, but does not believe that such deposits with its banks are subject to any unusual risk. EPOGEN ® and Aranesp ® are significant physician‑prescribed pharmaceuticals that are commonly administered during dialysis and are provided by Amgen. In September 2017, the Company entered into a purchase agreement with Vifor International AG that expires on December 31, 2022, pursuant to which it will provide the Company's clinics with epoetin alfa-epbx (Retacrit™) and Mircera ®, alternatives to EPOGEN and Aranesp, respectively.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Acquisitions On January 1, 2019, the Company acquired the assets of a dialysis center in Florida. The Company has a controlling interest in this joint venture. On March 1, 2019, the Company acquired the assets of a dialysis center in South Carolina. The Company has a controlling interest in this joint venture. The consideration transferred, on a combined basis for all acquisitions consummated during 2019 through the date of issuance of these financial statements, was as follows: Cash $ 6,590 Equity interests 4,655 Fair value of total consideration transferred $ 11,245 The amounts recognized as of the acquisition date, on a combined basis for all acquisitions consummated during 2019 through the date of issuance of these financial statements, for each major class of assets acquired and liabilities assumed were allocated preliminarily based on the estimated fair value, as follows: Property and equipment $ 1,657 Noncompete agreements 660 Goodwill 8,683 Other assets 245 Total consideration paid $ 11,245 The acquisition was made to expand the Company’s market presence in the indicated locations. The goodwill arising from these acquisitions was primarily attributable to future growth opportunities and any intangible assets that did not qualify for separate recognition, and goodwill of $4,774 is expected to be deductible for tax purposes. Pro forma information is not presented because such amounts are not significant. Divestitures The Company periodically divests the operating assets and liabilities of dialysis centers. The results of operations for these divestitures are included in the Company’s consolidated statements of operations through their respective sale consummation dates. On March 1, 2019, the Company sold 100% of the Company’s equity in two dialysis clinics in Florida and received a combined cash consideration for the sales of $3,300 . The transactions resulted in the recognition of a combined gain of $512 and a reduction of goodwill of $2,210 during the quarter ended March 31, 2019. On July 1, 2019, the Company sold 100% of the Company’s equity in two dialysis clinics in Maryland and received a combined cash consideration for the sales of $3,000 . The transactions resulted in the recognition of a combined gain of $264 and a reduction of goodwill of $2,155 during the quarter ended September 30, 2019. Held for Sale As of June 30, 2019, the Company reclassified the combined carrying value of assets of $14,061 , which met the criteria of held for sale and are expected to be sold within one year, to Current assets held for sale on the consolidated balance sheet. Key Employee Retention Plan In April 2019, the Company entered into retention agreements with certain officers and other employees of the Company to be paid in October 2019. The maximum amount payable under the plan is $2,005 , which is earned over the retention period. Consulting Agreement On March 25, 2019, the Company entered into an independent contractor's agreement with ECG Ventures, Inc., an entity wholly owned by a member of the Board. The board member provides consulting services to the Company on the terms set forth in the agreement. The agreement provides for a base fee of $100 per month during the term of the agreement, plus both a restatement fee and a performance fee, as well as reimbursement for travel and certain legal expenses. The Company incurred expenses of $656 during the three months ended June 30, 2019 relating to services provided under this consulting agreement. Refer to “ Note 15 - Debt ” and “ Note 22 - Certain Legal and Other Matters ” for additional subsequent events identified.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited) and Restatement of Previously Issued Unaudited Condensed Consolidated Financial Statements	Selected Quarterly Financial Data (Unaudited) Three Months Ended (in thousands, except for share data) December 31, 2018 September 30, 2018 June 30, 2018 March 31, 2018 December 31, 2017 September 30, 2017 June 30, 2017 March 31, 2017 (restated) (restated) (restated) (restated) (restated) (restated) (restated) Patient service operating revenues $ 207,806 $ 205,719 $ 205,952 $ 186,299 $ 190,509 $ 190,670 $ 177,890 $ 178,249 Net patient service operating revenues $ 207,806 $ 205,719 $ 205,952 $ 186,299 $ 187,331 $ 187,918 $ 177,459 $ 176,294 Operating Income (loss) $ 22,949 $ 24,110 $ (4,310 ) $ 12,573 $ 27,033 $ 33,224 $ 18,277 $ 11,674 Income (loss) before income taxes $ 19,590 $ 12,388 $ (10,710 ) $ 4,095 $ 21,549 $ 29,554 $ 7,922 $ 8,582 Net income (loss) attributable to American Renal Associates Holdings, Inc. $ (572 ) $ (734 ) $ (23,659 ) $ (3,802 ) $ (4,898 ) $ 7,496 $ (5,073 ) $ (2,122 ) Basic (loss) income per share attributable to American Renal Associates Holdings, Inc. $ (0.06 ) $ (0.04 ) $ (0.78 ) $ (0.10 ) $ (0.12 ) $ 0.26 $ (0.26 ) $ (0.41 ) Diluted (loss) income per share attributable to American Renal Associates Holdings, Inc. $ (0.06 ) $ (0.04 ) $ (0.78 ) $ (0.10 ) $ (0.12 ) $ 0.24 $ (0.26 ) $ (0.41 ) Restatement of Previously Issued Unaudited Condensed Consolidated Financial Statements The following tables present the restated unaudited quarterly condensed consolidated financial statements for each quarter-to-date and year-to-date interim period for the years ended December 31, 2018, 2017, and 2016. In the opinion of the Company's management, the unaudited condensed consolidated financial statements have been prepared on a basis consistent with the financial statements which appear elsewhere in these consolidated financial statements and include all adjustments, necessary for a fair statement of the financial position and results of operations for such unaudited periods. Historical results are not necessarily indicative of results to be expected in the future. See “ Note 3 - Restatement of Consolidated Financial Statements ” for additional information and a description of the adjustments and reclassifications in each category of restatements referenced by (a) through (h). Following are the Condensed Consolidated Balance Sheets for interim quarters ended 2018 (tables in thousands, except per share data): As of March 31, 2018 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 64,283 $ (10 ) f $ 64,273 Accounts receivable, less allowance for doubtful accounts 85,723 24,608 a 110,331 Inventories 7,642 (1,513 ) a,f 6,129 Prepaid expenses and other current assets 24,478 799 f 25,277 Income tax receivable 7,835 (7,835 ) d — Total current assets 189,961 16,049 206,010 Property and equipment, net of accumulated depreciation 168,682 — 168,682 Intangible assets, net of accumulated amortization 25,182 — 25,182 Other long-term assets 15,013 — 15,013 Goodwill 570,946 395 c 571,341 Total assets $ 969,784 $ 16,444 $ 986,228 Liabilities and Equity Accounts payable $ 40,885 $ — $ 40,885 Accrued compensation and benefits 27,160 — 27,160 Accrued expenses and other current liabilities 51,954 11,836 d 63,790 Current portion of long-term debt 45,121 — 45,121 Total current liabilities 165,120 11,836 176,956 Long-term debt, less current portion 512,822 — 512,822 Income tax receivable agreement payable 8,646 — 8,646 Other long-term liabilities 14,171 (24 ) d 14,147 Deferred tax liabilities 9,560 (9,138 ) d 422 Total liabilities 710,319 2,674 712,993 Commitments and contingencies Noncontrolling interests subject to put provisions 148,769 (8,978 ) b 139,791 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,437,507 issued and outstanding 195 — 195 Additional paid-in capital 68,632 29,611 b,c 98,243 Receivable from noncontrolling interests (515 ) — (515 ) Accumulated deficit (124,485 ) (15,001 ) a,b,c,d,f (139,486 ) Accumulated other comprehensive income (loss), net of tax 760 (214 ) d 546 Total American Renal Associates Holdings, Inc. deficit (55,413 ) 14,396 (41,017 ) Noncontrolling interests not subject to put provisions 166,109 8,352 a,b,c,d,f 174,461 Total equity 110,696 22,748 133,444 Total liabilities and equity $ 969,784 $ 16,444 $ 986,228 As of June 30, 2018 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 69,403 $ (10 ) f $ 69,393 Accounts receivable, less allowance for doubtful accounts 91,508 13,382 a 104,890 Inventories 6,535 — 6,535 Prepaid expenses and other current assets 20,338 (1,251 ) a,f 19,087 Income tax receivable 4,713 (4,713 ) d — Total current assets 192,497 7,408 199,905 Property and equipment, net of accumulated depreciation 167,621 — 167,621 Deferred tax assets — 4,596 d 4,596 Intangible assets, net of accumulated amortization 24,966 — 24,966 Other long-term assets 19,639 — 19,639 Goodwill 570,946 393 c 571,339 Total assets $ 975,669 $ 12,397 $ 988,066 Liabilities and Equity Accounts payable $ 52,849 $ — $ 52,849 Accrued compensation and benefits 30,881 — 30,881 Accrued expenses and other current liabilities 48,961 13,989 d 62,950 Current portion of long-term debt 46,660 — 46,660 Total current liabilities 179,351 13,989 193,340 Long-term debt, less current portion 509,983 — 509,983 Income tax receivable agreement payable 6,037 — 6,037 Other long-term liabilities 33,819 (3 ) d 33,816 Deferred tax liabilities 4,696 (4,696 ) d — Total liabilities 733,886 9,290 743,176 Commitments and contingencies Noncontrolling interests subject to put provisions 145,500 (4,763 ) e 140,737 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,458,837 issued and outstanding 195 — 195 Additional paid-in capital 69,170 24,169 b,c 93,339 Receivable from noncontrolling interests (477 ) — (477 ) Accumulated deficit (142,493 ) (20,652 ) a,b,c,d,f (163,145 ) Accumulated other comprehensive income (loss), net of tax 1,227 (214 ) d 1,013 Total American Renal Associates Holdings, Inc. deficit (72,378 ) 3,303 (69,075 ) Noncontrolling interests not subject to put provisions 168,661 4,567 a,b,c,d,f 173,228 Total equity 96,283 7,870 104,153 Total liabilities and equity $ 975,669 $ 12,397 $ 988,066 As of September 30, 2018 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 61,872 $ (10 ) f $ 61,862 Accounts receivable, less allowance for doubtful accounts 90,596 8,082 a 98,678 Inventories 6,382 — 6,382 Prepaid expenses and other current assets 20,608 (1,892 ) a,f 18,716 Income tax receivable 5,306 (5,306 ) d — Total current assets 184,764 874 185,638 Property and equipment, net of accumulated depreciation 168,346 — 168,346 Deferred tax assets — 4,596 d 4,596 Intangible assets, net of accumulated amortization 24,811 — 24,811 Other long-term assets 18,198 — 18,198 Goodwill 570,944 395 c 571,339 Total assets $ 967,063 $ 5,865 $ 972,928 Liabilities and Equity Accounts payable $ 54,023 $ — $ 54,023 Accrued compensation and benefits 34,658 — 34,658 Accrued expenses and other current liabilities 43,153 13,385 d 56,538 Current portion of long-term debt 47,206 — 47,206 Total current liabilities 179,040 13,385 192,425 Long-term debt, less current portion 506,750 — 506,750 Income tax receivable agreement payable 9,476 — 9,476 Other long-term liabilities 24,378 (3 ) d 24,375 Deferred tax liabilities 4,843 (4,843 ) d — Total liabilities 724,487 8,539 733,026 Commitments and contingencies Noncontrolling interests subject to put provisions 150,152 (8,916 ) b 141,236 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,514,777 issued and outstanding 195 — 195 Additional paid-in capital 65,965 27,252 b,c 93,217 Receivable from noncontrolling interests (1,340 ) — (1,340 ) Accumulated deficit (140,003 ) (23,875 ) a,b,c,d,f (163,878 ) Accumulated other comprehensive income (loss), net of tax 1,654 (214 ) d 1,440 Total American Renal Associates Holdings, Inc. deficit (73,529 ) 3,163 (70,366 ) Noncontrolling interests not subject to put provisions 165,953 3,079 a,b,c,d,f 169,032 Total equity 92,424 6,242 98,666 Total liabilities and equity $ 967,063 $ 5,865 $ 972,928 Following are the Condensed Consolidated Balance Sheets for the interim quarters ended 2017 (tables in thousands, except per share data): As of March 31, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 84,003 $ (10 ) f $ 83,993 Accounts receivable, less allowance for doubtful accounts 77,495 48,354 a 125,849 Inventories 4,648 — 4,648 Prepaid expenses and other current assets 18,217 — 18,217 Income tax receivable 9,415 (9,415 ) d — Total current assets 193,778 38,929 232,707 Property and equipment, net of accumulated depreciation 167,338 — 167,338 Deferred tax assets — 9,691 d 9,691 Intangible assets, net of accumulated amortization 25,681 — 25,681 Other long-term assets 7,472 — 7,472 Goodwill 573,147 (55 ) c 573,092 Total assets $ 967,416 $ 48,565 $ 1,015,981 Liabilities and Equity Accounts payable $ 24,605 $ — $ 24,605 Accrued compensation and benefits 26,092 — 26,092 Accrued expenses and other current liabilities 45,075 13,484 d 58,559 Current portion of long-term debt 45,559 — 45,559 Total current liabilities 141,331 13,484 154,815 Long-term debt, less current portion 520,364 — 520,364 Income tax receivable agreement payable 16,683 — 16,683 Other long-term liabilities 12,826 (3 ) d 12,823 Deferred tax liabilities 1,522 (1,522 ) d — Total liabilities 692,726 11,959 704,685 Commitments and contingencies Noncontrolling interests subject to put provisions 132,465 25,621 b 158,086 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 31,143,998 issued and outstanding 184 — 184 Additional paid-in capital 93,596 364 b,c 93,960 Receivable from noncontrolling interests (747 ) — (747 ) Accumulated deficit (129,897 ) (3,526 ) a,b,c,d,f (133,423 ) Accumulated other comprehensive income (loss), net of tax (744 ) — (744 ) Total American Renal Associates Holdings, Inc. deficit (37,608 ) (3,162 ) (40,770 ) Noncontrolling interests not subject to put provisions 179,833 14,147 a,b,c,d,f 193,980 Total equity 142,225 10,985 153,210 Total liabilities and equity $ 967,416 $ 48,565 $ 1,015,981 As of June 30, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 74,933 $ (11 ) f $ 74,922 Accounts receivable, less allowance for doubtful accounts 77,841 39,819 a 117,660 Inventories 4,960 — 4,960 Prepaid expenses and other current assets 23,150 — 23,150 Income tax receivable 10,254 (10,254 ) d — Total current assets 191,138 29,554 220,692 Property and equipment, net of accumulated depreciation 165,495 — 165,495 Deferred tax assets — 9,635 d 9,635 Intangible assets, net of accumulated amortization 25,638 — 25,638 Other long-term assets 8,885 — 8,885 Goodwill 573,147 (347 ) c 572,800 Total assets $ 964,303 $ 38,842 $ 1,003,145 Liabilities and Equity Accounts payable $ 28,184 $ — $ 28,184 Accrued compensation and benefits 28,654 — 28,654 Accrued expenses and other current liabilities 60,663 10,032 d 70,695 Current portion of long-term debt 45,711 — 45,711 Total current liabilities 163,212 10,032 173,244 Long-term debt, less current portion 516,442 — 516,442 Income tax receivable agreement payable 15,600 — 15,600 Other long-term liabilities 13,859 (3 ) d 13,856 Deferred tax liabilities 1,128 (1,128 ) d — Total liabilities 710,241 8,901 719,142 Commitments and contingencies Noncontrolling interests subject to put provisions 113,925 18,569 b 132,494 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 31,283,812 issued and outstanding 185 — 185 Additional paid-in capital 95,369 6,006 b,c 101,375 Receivable from noncontrolling interests (415 ) — (415 ) Accumulated deficit (132,003 ) (6,585 ) a,b,c,d,f (138,588 ) Accumulated other comprehensive income (loss), net of tax (1,420 ) — (1,420 ) Total American Renal Associates Holdings, Inc. deficit (38,284 ) (579 ) (38,863 ) Noncontrolling interests not subject to put provisions 178,421 11,951 a,b,c,d,f 190,372 Total equity 140,137 11,372 151,509 Total liabilities and equity $ 964,303 $ 38,842 $ 1,003,145 As of September 30, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 67,593 $ (10 ) f $ 67,583 Accounts receivable, less allowance for doubtful accounts 81,234 40,026 a 121,260 Inventories 4,672 — 4,672 Prepaid expenses and other current assets 17,133 — 17,133 Income tax receivable 8,071 (8,071 ) d — Total current assets 178,703 31,945 210,648 Property and equipment, net of accumulated depreciation 166,890 — 166,890 Deferred tax assets — 9,635 d 9,635 Intangible assets, net of accumulated amortization 25,488 — 25,488 Other long-term assets 8,636 — 8,636 Goodwill 572,702 (282 ) c 572,420 Total assets $ 952,419 $ 41,298 $ 993,717 Liabilities and Equity Accounts payable $ 33,863 $ — $ 33,863 Accrued compensation and benefits 31,767 — 31,767 Accrued expenses and other current liabilities 43,797 13,402 d 57,199 Current portion of long-term debt 44,189 — 44,189 Total current liabilities 153,616 13,402 167,018 Long-term debt, less current portion 514,846 — 514,846 Income tax receivable agreement payable 11,900 — 11,900 Other long-term liabilities 15,713 — 15,713 Deferred tax liabilities 1,110 (1,110 ) d — Total liabilities 697,185 12,292 709,477 Commitments and contingencies Noncontrolling interests subject to put provisions 110,988 22,728 b 133,716 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 31,314,217 issued and outstanding 186 — 186 Additional paid-in capital 94,158 1,201 b,c 95,359 Receivable from noncontrolling interests (484 ) — (484 ) Accumulated deficit (124,020 ) (7,180 ) a,b,c,d,f (131,200 ) Accumulated other comprehensive income (loss), net of tax (1,447 ) — (1,447 ) Total American Renal Associates Holdings, Inc. deficit (31,607 ) (5,979 ) (37,586 ) Noncontrolling interests not subject to put provisions 175,853 12,257 a,b,c,d,f 188,110 Total equity 144,246 6,278 150,524 Total liabilities and equity $ 952,419 $ 41,298 $ 993,717 Following are the Condensed Consolidated Balance Sheets for the interim quarters ended 2016 (tables in thousands, except per share data): As of March 31, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 95,965 $ (4 ) f $ 95,961 Accounts receivable, less allowance for doubtful accounts 75,831 43,492 a 119,323 Inventories 5,515 — 5,515 Prepaid expenses and other current assets 19,507 (112 ) c 19,395 Income tax receivable 2,661 (2,661 ) d — Total current assets 199,479 40,715 240,194 Property and equipment, net of accumulated depreciation 151,204 — 151,204 Intangible assets, net of accumulated amortization 25,877 — 25,877 Other long-term assets 6,574 — 6,574 Goodwill 569,315 (54 ) c 569,261 Total assets $ 952,449 $ 40,661 $ 993,110 Liabilities and Equity Accounts payable $ 23,857 $ — $ 23,857 Accrued compensation and benefits 21,496 — 21,496 Accrued expenses and other current liabilities 31,110 14,100 d 45,210 Current portion of long-term debt 27,171 — 27,171 Total current liabilities 103,634 14,100 117,734 Long-term debt, less current portion 661,369 — 661,369 Other long-term liabilities 9,927 — 9,927 Deferred tax liabilities 15,096 (7,142 ) d 7,954 Total liabilities 790,026 6,958 796,984 Commitments and contingencies Noncontrolling interests subject to put provisions 107,414 17,558 b 124,972 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 29,770,000 issued and outstanding 98 — 98 Additional paid-in capital 457 6,396 b,c 6,853 Receivable from noncontrolling interests (605 ) — (605 ) Accumulated deficit (124,505 ) (3,435 ) a,b,c,d,f (127,940 ) Accumulated other comprehensive income (loss), net of tax (401 ) — (401 ) Total American Renal Associates Holdings, Inc. deficit (124,956 ) 2,961 (121,995 ) Noncontrolling interests not subject to put provisions 179,965 13,184 a,b,c,d,f 193,149 Total equity 55,009 16,145 71,154 Total liabilities and equity $ 952,449 $ 40,661 $ 993,110 As of June 30, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 93,268 $ (6 ) f $ 93,262 Accounts receivable, less allowance for doubtful accounts 76,904 54,081 a 130,985 Inventories 4,790 — 4,790 Prepaid expenses and other current assets 14,977 (75 ) c 14,902 Income tax receivable 144 (144 ) d — Total current assets 190,083 53,856 243,939 Property and equipment, net of accumulated depreciation 160,887 — 160,887 Intangible assets, net of accumulated amortization 25,938 — 25,938 Other long-term assets 6,174 — 6,174 Goodwill 569,930 (54 ) c 569,876 Total assets $ 953,012 $ 53,802 $ 1,006,814 Liabilities and Equity Accounts payable $ 23,515 $ — $ 23,515 Accrued compensation and benefits 25,469 — 25,469 Accrued expenses and other current liabilities 45,642 11,176 d 56,818 Current portion of long-term debt 40,579 — 40,579 Total current liabilities 135,205 11,176 146,381 Long-term debt, less current portion 517,798 — 517,798 Income tax receivable agreement payable 27,800 — 27,800 Other long-term liabilities 10,361 (6 ) d 10,355 Deferred tax liabilities 7,169 785 d 7,954 Total liabilities 698,333 11,955 710,288 Commitments and contingencies Noncontrolling interests subject to put provisions 134,762 16,862 b 151,624 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 30,845,109 issued and outstanding 184 — 184 Additional paid-in capital 72,405 9,444 b,c 81,849 Receivable from noncontrolling interests (498 ) — (498 ) Accumulated deficit (133,597 ) (1,402 ) a,b,c,d,f (134,999 ) Accumulated other comprehensive income (loss), net of tax (301 ) — (301 ) Total American Renal Associates Holdings, Inc. deficit (61,807 ) 8,042 (53,765 ) Noncontrolling interests not subject to put provisions 181,724 16,943 a,b,c,d,f 198,667 Total equity 119,917 24,985 144,902 Total liabilities and equity $ 953,012 $ 53,802 $ 1,006,814 As of September 30, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 105,149 $ (11 ) f $ 105,138 Accounts receivable, less allowance for doubtful accounts 77,253 53,265 a 130,518 Inventories 4,468 — 4,468 Prepaid expenses and other current assets 12,951 (37 ) f 12,914 Income tax receivable 4,656 (4,656 ) d — Total current assets 204,477 48,561 253,038 Property and equipment, net of accumulated depreciation 165,132 — 165,132 Intangible assets, net of accumulated amortization 25,943 — 25,943 Other long-term assets 6,593 — 6,593 Goodwill 573,107 (55 ) c 573,052 Total assets $ 975,252 $ 48,506 $ 1,023,758 Liabilities and Equity Accounts payable $ 23,277 $ — $ 23,277 Accrued compensation and benefits 29,092 — 29,092 Accrued expenses and other current liabilities 54,031 5,357 d 59,388 Current portion of long-term debt 43,582 — 43,582 Total current liabilities 149,982 5,357 155,339 Long-term debt, less current portion 520,017 — 520,017 Income tax receivable agreement payable 15,670 — 15,670 Other long-term liabilities 11,262 — 11,262 Deferred tax liabilities 6,722 1,232 d 7,954 Total liabilities 703,653 6,589 710,242 Commitments and contingencies Noncontrolling interests subject to put provisions 140,336 11,580 b 151,916 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 30,868,050 issued and outstanding 184 — 184 Additional paid-in capital 69,765 14,400 b,c 84,165 Receivable from noncontrolling interests (562 ) — (562 ) Accumulated deficit (121,527 ) (699 ) a,b,c,d,f (122,226 ) Accumulated other comprehensive income (loss), net of tax (201 ) — (201 ) Total American Renal Associates Holdings, Inc. deficit (52,341 ) 13,701 (38,640 ) Noncontrolling interests not subject to put provisions 183,604 16,636 a,b,c,d,f 200,240 Total equity 131,263 30,337 161,600 Total liabilities and equity $ 975,252 $ 48,506 $ 1,023,758 Following are the Condensed Consolidated Statements of Operations for the interim quarters ended 2018 (tables in thousands, except share and per share data): For the Three Months Ended March 31, 2018 As Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 194,672 $ (8,373 ) a $ 186,299 Operating expenses: Patient care costs 133,731 346 a 134,077 General and administrative 24,960 107 a,c,f 25,067 Transaction-related costs 856 — 856 Depreciation and amortization 9,623 — 9,623 Certain legal and other matters 4,103 — 4,103 Total operating expenses 173,273 453 173,726 Operating income 21,399 (8,826 ) 12,573 Interest expense, net (7,457 ) — (7,457 ) Change in fair value of income tax receivable agreement (1,021 ) — (1,021 ) Income before income taxes 12,921 (8,826 ) 4,095 Income tax benefit (792 ) (2,277 ) d (3,069 ) Net income 13,713 (6,549 ) 7,164 Less: Net income attributable to noncontrolling interests (14,623 ) 3,657 e (10,966 ) Net loss attributable to American Renal Associates Holdings, Inc. (910 ) (2,892 ) (3,802 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests 582 (85 ) b 497 Net loss attributable to common shareholders $ (328 ) $ (2,977 ) $ (3,305 ) Loss per share: Basic $ (0.01 ) $ (0.10 ) Diluted $ (0.01 ) $ (0.10 ) Weighted-average number of common shares outstanding Basic 31,800,553 31,800,553 Diluted 31,800,553 31,800,553 For the Three Months Ended June 30, 2018 As Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 217,178 $ (11,226 ) a $ 205,952 Operating expenses: Patient care costs 140,562 906 a 141,468 General and administrative 26,803 (369 ) b,c 26,434 Depreciation and amortization 9,814 — 9,814 Certain legal and other matters 32,546 — f 32,546 Total operating expenses 209,725 537 210,262 Operating income 7,453 (11,763 ) (4,310 ) Interest expense, net (8,131 ) (5 ) f (8,136 ) Change in fair value of income tax receivable agreement 1,736 — 1,736 Income before income taxes 1,058 (11,768 ) (10,710 ) Income tax benefit (1,219 ) (1,108 ) d (2,327 ) Net income (loss) 2,277 (10,660 ) (8,383 ) Less: Net income attributable to noncontrolling interests (20,285 ) 5,009 e (15,276 ) Net loss attributable to American Renal Associates Holdings, Inc. (18,008 ) (5,651 ) (23,659 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (884 ) (364 ) b (1,248 ) Net loss attributable to common shareholders $ (18,892 ) $ (6,015 ) $ (24,907 ) Loss per share: Basic $ (0.59 ) $ (0.78 ) Diluted $ (0.59 ) $ (0.78 ) Weighted-average number of common shares outstanding Basic 31,932,705 31,932,705 Diluted 31,932,705 31,932,705 For the Six Months Ended June 30, 2018 As Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 411,850 $ (19,599 ) a $ 392,251 Operating expenses: Patient care costs 274,293 1,252 a 275,545 General and administrative 51,763 (262 ) c 51,501 Transaction-related costs 856 — 856 Depreciation and amortization 19,437 — 19,437 Certain legal and other matters 36,649 — 36,649 Total operating expenses 382,998 990 383,988 Operating income 28,852 (20,589 ) 8,263 Interest expense, net (15,588 ) (5 ) f (15,593 ) Change in fair value of income tax receivable agreement 715 — 715 Income before income taxes 13,979 (20,594 ) (6,615 ) Income tax benefit (2,011 ) (3,385 ) d (5,396 ) Net income 15,990 (17,209 ) (1,219 ) Less: Net income attributable to noncontrolling interests (34,908 ) 8,666 e (26,242 ) Net loss attributable to American Renal Associates Holdings, Inc. (18,918 ) (8,543 ) (27,461 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (302 ) (449 ) b (751 ) Net loss attributable to common shareholders $ (19,220 ) $ (8,992 ) $ (28,212 ) Loss per share: Basic $ (0.60 ) $ (0.89 ) Diluted $ (0.60 ) $ (0.89 ) Weighted-average number of common shares outstanding Basic 31,877,286 31,877,286 Diluted 31,877,286 31,877,286 For the Three Months Ended September 30, 2018 As Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 211,019 $ (5,300 ) a $ 205,719 Operating expenses: Patient care costs 145,300 639 a 145,939 General and administrative 24,619 — 24,619 Depreciation and amortization 10,023 — 10,023 Certain legal and other matters 1,028 — 1,028 Total operating expenses 180,970 639 181,609 Operating income 30,049 (5,939 ) 24,110 Interest expense, net (8,241 ) (1 ) f (8,242 ) Change in fair value of income tax receivable agreement (3,480 ) — (3,480 ) Income before income taxes 18,328 (5,940 ) 12,388 Income tax expense (benefit) 34 (158 ) d (124 ) Net income 18,294 (5,782 ) 12,512 Less: Net income attributable to noncontrolling interests (15,804 ) 2,558 e (13,246 ) Net income (loss) attributable to American Renal Associates Holdings, Inc. 2,490 (3,224 ) (734 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (481 ) (99 ) b (580 ) Net income (loss) attributable to common shareholders $ 2,009 $ (3,323 ) $ (1,314 ) Earnings (loss) per share: Basic $ 0.06 $ (0.04 ) Diluted $ 0.06 $ (0.04 ) Weighted-average number of common shares outstanding Basic 32,005,544 32,005,544 Diluted 34,578,592 32,005,544 For the Nine Months Ended September 30, 2018 As Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 622,869 $ (24,899 ) a $ 597,970 Operating expenses: Patient care costs 419,593 1,891 a 421,484 General and administrative 76,382 (262 ) c 76,120 Transaction-related costs 856 — 856 Depreciation and amortization 29,460 — 29,460 Certain legal and other matters 37,677 — 37,677 Total operating expenses 563,968 1,629 565,597 Operating income 58,901 (26,528 ) 32,373 Interest expense, net (23,829 ) (6 ) f (23,835 ) Change in fair value of income tax receivable agreement (2,765 ) — (2,765 ) Income before income taxes 32,307 (26,534 ) 5,773 Income tax benefit (1,977 ) (3,543 ) d (5,520 ) Net income 34,284 (22,991 ) 11,293 Less: Net income attributable to noncontrolling interests (50,712 ) 11,224 e (39,488 ) Net loss attributable to American Renal Associates Holdings, Inc. (16,428 ) (11,767 ) (28,195 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (783 ) (548 ) b (1,331 ) Net loss attributable to common shareholders $ (17,211 ) $ (12,315 ) $ (29,526 ) Loss per share: Basic $ (0.54 ) $ (0.93 ) Diluted $ (0.54 ) $ (0.93 ) Weighted-average number of common shares outstanding Basic 31,912,934 31,912,934 Diluted 31,912,934 31,912,934 Following are the Condensed Consolidated Statements of Operations for the interim quarters ended 2017 (tables in thousands, except share and per share data): For the Three Months Ended March 31, 2017 As Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 178,632 $ (383 ) a $ 178,249 Provision for uncollectible accounts (1,607 ) (348 ) a (1,955 ) Net patient service operating revenues 177,025 (731 ) 176,294 Operating expenses: Patient care costs 120,301 — 120,301 General and administrative 31,244 65 h 31,309 Depreciation and amortization 9,074 — 9,074 Certain legal and other matters 3,936 — 3,936 Total operating expenses 164,555 65 164,620 Operating income 12,470 (796 ) 11,674 Interest expense, net (7,609 ) — (7,609 ) Change in fair value of income tax receivable agreement 4,517 — 4,517 Income before income taxes 9,378 (796 ) 8,582 Income tax benefit (3,524 ) 344 d,h (3,180 ) Net income 12,902 (1,140 ) 11,762 Less: Net income attributable to noncontrolling interests (14,153 ) 269 e (13,884 ) Net loss attributable to American Renal Associates Holdings, Inc. (1,251 ) (871 ) (2,122 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (11,083 ) 676 b (10,407 ) Net loss attributable to common shareholders $ (12,334 ) $ (195 ) $ (12,529 ) Loss per share: Basic $ (0.40 ) $ (0.41 ) Diluted $ (0.40 ) $ (0.41 ) Weighted-average number of common shares outstanding Basic 30,907,482 30,907,482 Diluted 30,907,482 30,907,482 For the Three Months Ended June 30, 2017 As Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 187,602 $ (9,712 ) a $ 177,890 Provision for uncollectible accounts (1,610 ) 1,179 a (431 ) Net patient service operating revenues 185,992 (8,533 ) 177,459 Operating expenses: Patient care costs 118,059 509 g 118,568 General and administrative 26,381 (163 ) c,g,h 26,218 Transaction-related costs 717 — 717 Depreciation and amortization 9,382 — 9,382 Certain legal and other matters 4,297 — 4,297 Total operating expenses 158,836 346 159,182 Operating income 27,156 (8,879 ) 18,277 Interest expense, net (7,188 ) — (7,188 ) Loss on early extinguishment of debt (526 ) — (526 ) Change in fair value of income tax receivable agreement (2,641 ) — (2,641 ) Income before income taxes 16,801 (8,879 ) 7,922 Income tax expense (benefit) 410 (2,247 ) d,h (1,837 ) Net income 16,391 (6,632 ) 9,759 Less: Net income attributable to noncontrolling interests (18,497 ) 3,665 e (14,832 ) Net loss attributable to American Renal Associates Holdings, Inc. (2,106 ) (2,967 ) (5,073 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (2,527 ) (357 ) b (2,884 ) Net loss attributable to common shareholders $ (4,633 ) $ (3,324 ) $ (7,957 ) Loss per share: Basic $ (0.15 ) $ (0.26 ) Diluted $ (0.15 ) $ (0.26 ) Weighted-average number of common shares outstanding Basic 30,986,689 30,986,689 Diluted 30,986,689 30,986,689 For the Six Months Ended June 30, 2017 As Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 366,234 $ (10,095 ) a $ 356,139 Provision for uncollectible accounts (3,217 ) 831 a (2,386 ) Net patient service operating revenues 363,017 (9,264 ) 353,753 Operating expenses: Patient care costs 238,360 509 g 238,869 General and administrative 57,625 (98 ) c,g,h 57,527 Transaction-related costs 717 — 717 Depreciation and amortization 18,456 — 18,456 Certain legal and other matters 8,233 — 8,233 Total operating expenses 323,391 411 323,802 Operating income 39,626 (9,675 ) 29,951 Interest expense, net (14,797 ) — (14,797 ) Loss on early extinguishment of debt (526 ) — (526 ) Change in fair value of income tax receivable agreement 1,876 — 1,876 Income before income taxes 26,179 (9,675 ) 16,504 Income tax benefit (3,114 ) (1,903 ) d,h (5,017 ) Net income 29,293 (7,772 ) 21,521 Less: Net income attributable to noncontrolling interests (32,650 ) 3,934 e (28,716 ) Net loss attributable to American Renal Associates Holdings, Inc. (3,357 ) (3,838 ) (7,195 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (13,610 ) 319 b (13,291 ) Net loss attributable to common shareholders $ (16,967 ) $ (3,519 ) $ (20,486 ) Loss per share: Basic $ (0.55 ) $ (0.66 ) Diluted $ (0.55 ) $ (0.66 ) Weighted-average number of common shares outstanding Basic 30,947,304 30,947,304 Diluted 30,947,304 30,947,304 For the Three Months Ended September 30, 2017 As Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 189,497 $ 1,173 a $ 190,670 Provision for uncollectible accounts (1,786 ) (966 ) a (2,752 ) Net patient service operating revenues 187,711 207 187,918 Operating expenses: Patient care costs 119,599 140 g 119,739 General and administrative 22,292 (256 ) c,g,h 22,036 Depreciation and amortization 9,438 — 9,438 Certain legal and other matters 3,481 — 3,481 Total operating expenses 154,810 (116 ) 154,694 Operating income 32,901 323 33,224 Interest expense, net (7,255 ) — (7,255 ) Change in fair value of income tax receivable agreement 3,585 — 3,585 Income before income taxes 29,231 323 29,554 Income tax expense 2,559 1,204 d,h 3

SCHEDULE II - VALUATION AND QUA

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 31, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS	SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (in thousands) Balance at Beginning of the Year Amounts charged to income Amounts written off Balance at End of Year Allowance for uncollectible accounts: Year ended December 31, 2016, as restated $ 9,563 $ 17,745 $ (17,575 ) $ 9,733 Year ended December 31, 2017, as restated $ 9,733 $ 19,503 $ (20,560 ) $ 8,676 Year ended December 31, 2018 $ 8,676 $ — $ (5,406 ) $ 3,270

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The Company's consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries and variable interest entities that operate its clinics (“joint ventures”). For its joint ventures, the Company has determined that a majority voting interest and/or contractual rights granted to it provides the Company with the ability to direct the activities of these entities, and therefore the Company has determined that it is the primary beneficiary of these entities. Accordingly, the financial results of these joint ventures are fully consolidated into the Company’s operating results. The equity interests of the outside investors in the equity and results of operations of these consolidated entities are accounted for and presented as noncontrolling interests. All significant intercompany balances and transactions of the Company's wholly owned subsidiaries and joint ventures, including management fees from subsidiaries, are eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S GAAP requires the use of estimates and assumptions that affect the reported amounts of revenues, expenses, assets, liabilities, and contingencies. Although actual results in subsequent periods will differ from these estimates, such estimates are developed based on the best information available to management and management’s best judgments at the time made. All significant assumptions and estimates underlying the reported amounts in the consolidated financial statements and accompanying notes are regularly reviewed and updated. Changes in estimates are reflected in the financial statements based upon ongoing actual experience, trends, or subsequent settlements and realizations, depending on the nature and predictability of the estimates and contingencies. The most significant assumptions and estimates underlying these financial statements and accompanying notes involve revenue recognition and provisions for uncollectible accounts, impairments and valuation adjustments, the useful lives of property and equipment, fair value measurements, accounting for income taxes, acquisition accounting valuation estimates, commitments and contingencies and stock‑based compensation. Specific risks and contingencies related to these estimates are further addressed within the notes to the consolidated financial statements.
Segment Information	Segment Information Accounting pronouncements establish standards for the manner in which public companies report information about operating segments in annual and interim financial statements. Operating segments are identified as components of an enterprise for which separate discrete financial information is evaluated regularly by the chief operating decision‑maker in making decisions about how to allocate resources and assess performance. Based on its operating management and financial reporting structure, the Company has determined that it is operating as one reportable business segment, the ownership and operation of dialysis clinics, all of which are located in the United States.
Net Patient Service Operating Revenues and Accounts Receivable	Net Patient Service Operating Revenues and Accounts Receivable The major component of the Company's revenues is derived from dialysis treatments and related services. Sources of payment of revenues are principally from government-based programs, including Medicare, Medicaid and state workers' compensation programs, commercial insurance payors and other sources such as the U.S. Department of Veterans Affairs (the “VA”), hospitals as well as patient self-pay. Net patient service operating revenues are reported at the amounts that reflect the consideration to which the Company expects to be entitled in exchange for providing dialysis treatments and related services. Amounts may include variable consideration for discounts, price concessions and retroactive revenue adjustments due to new information obtained, such as actual payment receipt, as well as settlement of audits, reviews and investigations. Third-party payors, patients and other payors are generally billed at least monthly, typically in the month the dialysis treatment is performed, and payment is due upon receipt. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is defined as the unit of account under ASC 606, Revenue from Contracts with Customers . The Company has determined that one performance obligation exists, a single dialysis treatment, which is satisfied over time as a dialysis treatment is provided. While the Company provides patients with other related services, they are considered a bundle of interrelated services with dialysis treatment as the primary service. Revenue is measured using the output method, which is based upon the delivery of a dialysis treatment to the patient. The Company believes that this method reflects the satisfaction of the performance obligation. All performance obligations are satisfied at the end of each reporting period. The Company maintains a usual and customary fee schedule for dialysis treatment and other related services. However, the transaction price is typically recorded at a discount to the fee schedule. The transaction prices for Medicare and Medicaid programs are based on predetermined net realizable rates per treatment that are established by statutes or regulations. For Medicare programs, the Company receives 80% of the payment directly from Medicare as established under the government’s bundled payment system. The transaction prices for contracted payors are based on contracted rates. For other payors, the Company determines the transaction price based on usual and customary rates for services provided, reduced by contractual adjustments provided to third-party payors, discounts provided to uninsured patients in accordance with the Company’s policy, and/or implicit price concessions. The Company determines its estimate of implicit price concessions based on its historical collection experience with each payor, and where no prior experience exists, it considers information from the patient's health plan. Amounts billed that have not yet been collected and that meet the conditions for unconditional right to payment are presented as net accounts receivable. Contractual adjustments result from differences between the rates charged for services performed and expected reimbursements from third-party payors. Contractual adjustments and discounts with third-party payors are considered variable consideration and are included in the determination of the estimated transaction price for providing patient care. In assessing the probability of these claim payments, the Company considers previous payment history when recording a reserve, generally at the patient level, that results in an estimate of expected revenue such that it is probable that a significant revenue reversal will not occur in future periods. There are significant challenges associated with estimating revenue, with certain transactions taking several years to resolve. Estimates are subject to ongoing insurance coverage changes, geographic coverage differences, differing interpretations of contract coverage and other payor issues, as well as other issues including determining applicable primary and secondary coverage, changes in patient coverage and coordination of benefits. As these estimates are refined over time, both positive and negative adjustments to revenue are recognized in the current period. Settlements with third-party payors for retroactive adjustments due to audits, reviews or investigations are considered variable consideration and are included in the determination of the estimated transaction price for providing dialysis treatments and related services. These settlements are estimated based on the terms of the payment agreement with the payor, correspondence from the payor and the Company’s historical settlement activity, including an assessment to ensure that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty periods end and as adjustments become known (i.e., new information becomes available), or as years are settled or are no longer subject to such audits, reviews and investigations. The Company recorded $5,521 of revenue during the year ended December 31, 2018 related to adjustments arising from a change in the transaction price in instances where the performance obligation was satisfied in a previous period related to a payor. Excluding the impact of this payor, adjustments arising from a change in the transaction price in instances where the performance obligation was satisfied in a previous period, were immaterial for the year ended December 31, 2018 . These changes in transaction price are mostly attributable to an adjustment for balances with non-contracted payors. When the Company obtains new information, such as actual cash receipts, it adjusts the estimated transaction price.
Contingencies	Contingencies The Company and its subsidiaries are defendants in various legal actions in the normal course of business and legal actions relating the restatement of previously issued consolidated financial statements as described in “Note 3 - Restatement of Consolidated Financial Statements.” The Company records a liability when it believes that it is probable that a loss has been incurred, and the amount can be reasonably estimated. If it determines that a loss is reasonably possible and the loss or range of loss can be estimated, the Company discloses the possible loss in the Notes to the Consolidated Financial Statements. The Company evaluates, on a quarterly basis, developments in its legal matters that could affect the amount of liability that has been previously accrued, and the matters and related reasonably possible losses disclosed, and make adjustments and changes to its disclosures as appropriate. Significant judgment is required to determine both likelihood of there being and the estimated amount of a loss related to such matters. Until the final resolution of such matters, there may be an exposure to loss in excess of the amount recorded, and such amounts could be material. Should any of the Company's estimates and assumptions change or prove to have been incorrect, it could have a material impact on its business, consolidated financial position, results of operations, or cash flows.
Fair Value Measurements	Fair Value Measurements The Company estimates the fair value of certain assets, liabilities and noncontrolling interests subject to put provisions based upon certain valuation techniques that include observable or unobservable inputs and assumptions that market participants would use in valuing these assets, liabilities and noncontrolling interests. The Company also has classified certain assets, liabilities and noncontrolling interests subject to put provisions that are measured at fair value into the appropriate fair value hierarchy levels. The determination of the fair value of these assets and liabilities is a critical accounting estimate that involves significant judgments and assumptions and may not be indicative of the actual values at which these assets could be sold to a third party or at which these obligations could be settled.
Inventories	Inventories Inventories are stated at the lower of cost (first‑in, first‑out method) or market, and consist principally of pharmaceuticals and dialysis‑related consumable supplies.
Property and Equipment	Property and Equipment We account for property and equipment at cost less accumulated depreciation and amortization. Depreciation is being recorded over the remaining useful lives. Property and equipment acquired as part of an acquisition are recorded at fair value and other purchases are stated at cost with depreciation calculated using the straight‑line method over their estimated useful lives as follows: Buildings 39 years Leasehold improvements Shorter of lease term or useful lives Equipment and information systems 3 to 10 years Upon retirement or sale, the cost and related accumulated depreciation are removed from the accounts, and any resulting gain or loss is credited or charged to income. Maintenance and repairs are charged to expense as incurred. Included in construction in progress are amounts expended for leasehold improvement costs incurred for new dialysis clinics and clinic expansions, in each case, that are not in service as of December 31 of the applicable year.
Amortizable Intangible Assets	Amortizable Intangible Assets Amortizable intangible assets include noncompete agreements, certificates of need and right of first refusal waivers. Each of these assets is amortized on a straight‑line basis over the term of the agreement, which is generally 5 to 10 years.
Identified Non Amortizable Intangible Assets and Goodwill	Identified Non‑Amortizable Intangible Assets and Goodwill Goodwill represents the excess cost of a business acquisition over the fair value of the net assets acquired. Indefinite‑life identifiable intangible assets consist primarily of trademarks are considered indefinite when they are expected to generate cash flows indefinitely. Goodwill and indefinite‑life identifiable intangible assets are not amortized but are tested for impairment at least annually. The Company performs its annual review in the fourth quarter of each year, or more frequently if indicators of potential impairment exist, to determine if the carrying value of the recorded goodwill or indefinite lived intangible assets is greater than the fair value, indicating impairment. If an asset is impaired, the difference between the carrying value of the asset reflected on the financial statements and its current fair value is recognized as an expense in the period in which the impairment occurs. The Company elected to early adopt Accounting Standards Update (“ASU”) 2017-04, Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment , effective as of the annual review performed in the fourth quarter of 2017. The new guidance removes the requirement to perform a hypothetical purchase price allocation to measure goodwill impairment (Step 2). Under the new guidance, a goodwill impairment is calculated as the amount by which a reporting unit’s carrying value exceeds its fair value. The Company has determined it has one reporting unit for goodwill impairment testing purposes as it aggregated its dialysis clinics due to their similar operations components and economic characteristics of the Company. Each annual reporting period, the Company can elect to initially perform a qualitative assessment to determine whether it is necessary to perform the quantitative goodwill impairment test. If the Company believes, as a result of its qualitative assessment, that it is not more likely than not that the fair value of the reporting unit is less than its carrying amount, then the quantitative goodwill impairment test is unnecessary. If the Company elects to bypass the qualitative assessment option, or if potential impairment circumstances are considered to exist, the Company will perform the quantitative goodwill impairment test. The Company performs the quantitative goodwill impairment test using a discounted cash flow analysis, comparing the fair value with the carrying amount of the reporting unit. Such analysis is based on macro-economic factors and research, current financial information such as current results of operations and balance sheets, and projected financial results, which include only anticipated growth from current operations. The weighted average cost of capital method is used to determine the discount rate and the Gordon Growth Model is used to determine the residual value necessary for the discounted cash flow method. Changes in the estimates or assumptions used in these models could impact the results of the valuations. If the carrying amount of the reporting unit exceeds its fair value, the Company would record the difference as an impairment loss as an expense in the period in which the impairment occurred. The carrying value of goodwill included on the Company's consolidated balance sheet as of the annual impairment test date of October 1, 2018 was $571,339 . The Company’s quantitative impairment test performed for goodwill in 2018 indicated that no impairment charge was necessary for the year ended December 31, 2018 . Based on similar assessments and tests performed in the years ended December 31, 2017 , and 2016 , no impairment was identified for those respective years. The impairment test for indefinite-lived intangibles other than goodwill consists of a comparison of the fair value of the indefinite-lived intangible asset to the carrying value of the asset as of the impairment testing date. The Company estimates the fair value of its indefinite-lived intangibles using a discounted cash flow model based on its best estimate of amounts and timing of future revenues and cash flows and its most recent business and strategic plans, and compares the estimated fair value to the carrying value of the asset. For its 2018 impairment assessment, which occurred as of October 1, 2018, the Company performed quantitative assessments for all indefinite‑lived intangible assets.
Impairment of Long-Lived Assets	Impairment of Long‑Lived Assets Long‑lived assets include property and equipment and finite‑lived intangibles. In the event that facts and circumstances indicate that these assets may be impaired, an evaluation of recoverability at the lowest asset group level would be performed. If an evaluation is required, the estimated future undiscounted cash flows associated with the asset would be compared to the asset’s carrying amount to determine if a write‑down to fair value is required. The lowest level for which identifiable cash flows exist is the operating clinic level.
Assets Held for Sale	Assets Held for Sale The Company classifies its long-lived assets to be sold as held for sale in the period (i) it has approved and committed to a plan to sell the asset, (ii) the asset is available for immediate sale in its present condition, (iii) an active program to locate a buyer and other actions required to sell the asset have been initiated, (iv) the sale of the asset is probable, (v) the asset is being actively marketed for sale at a price that is reasonable in relation to its current fair value and (vi) it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. The Company initially measures a long-lived asset that is classified as held for sale at the lower of its carrying value or fair value less any costs to sell. Any loss resulting from this measurement is recognized in the period in which the held for sale criteria are met. Conversely, gains are not recognized on the sale of a long-lived asset until the date of sale. Upon designation as an asset held for sale, the Company stops recording depreciation expense on the asset. The Company assesses the fair value of a long-lived asset less any costs to sell at each reporting period and until the asset is no longer classified as held for sale.
Income Taxes	Income Taxes The Company accounts for income taxes under the liability approach. Under this approach, deferred tax assets and liabilities are recognized based upon temporary differences between the financial statement and tax bases of assets and liabilities, as measured by the enacted tax rates, which will be in effect when these differences reverse. Deferred tax expense or benefit is the result of changes in deferred tax assets and liabilities between reporting periods. A valuation allowance is established when, based on an evaluation of objectively verifiable evidence, there is a likelihood that some portion or all of the deferred tax assets will not be realized. The Company is not taxed on the share of pre‑tax income attributable to noncontrolling interests, and net income attributable to noncontrolling interests in its consolidated financial statements has not been presented net of income taxes attributable to these noncontrolling interests. Therefore, the Company’s income tax provision (benefit) relates to its share of pre‑tax income (losses) from its ownership interest in its subsidiaries as these entities are pass‑through entities for tax purposes. The Company recognizes a tax position in its financial statements when that tax position, based upon its technical merits, is more likely than not to be sustained upon examination by the relevant taxing authority. Once the recognition threshold is met, the tax position is then measured to determine the actual amount of benefit to recognize in the financial statements. In addition, the recognition threshold of more‑likely‑than‑not must continue to be met in each reporting period to support continued recognition of the tax benefit. Tax positions that previously failed to meet the more‑likely‑than‑not recognition threshold are recognized in the first financial reporting period in which that threshold is met. Previously recognized tax positions that no longer meet the more‑likely‑than‑not recognition threshold are derecognized in the financial reporting period in which that threshold is no longer met. The Company recognizes interest and penalties related to unrecorded tax positions in its income tax expense.
Noncontrolling Interests	Noncontrolling Interests The Company owns a controlling interest in the majority of its clinics as of December 31, 2018 , and its joint venture partners own the remaining noncontrolling interests. The Company is required to treat noncontrolling interests (other than noncontrolling interests subject to put provisions) as a separate component of equity, but apart from its own equity, and not as a liability or other item outside of equity. The Company is also required to present separately consolidated net income (loss) attributable to ARA and to noncontrolling interests on the face of the consolidated statement of income. In addition, changes in the Company's ownership interest while it retains a controlling financial interest are prospectively accounted for as equity transactions. The Company is also required to expand disclosures in the financial statements to include a reconciliation of the beginning and ending balances of the equity attributable to the Company and the noncontrolling owners and a schedule showing the effects of changes in the Company's ownership interest in a subsidiary on the equity attributable to the Company. Further, the Company is also required to classify securities with redemption features that are not solely within the Company’s control, such as the Company’s noncontrolling interests that are subject to put provisions, outside of permanent equity. These noncontrolling interests subject to put provisions are recorded at the greater of the noncontrolling interest balance determined pursuant to ASC 810-10, Consolidation , or the redemption value. Changes in the fair value of noncontrolling interests subject to put provisions are accounted for as equity transactions. Changes in the redemption value over fair value are recognized as reductions of earnings available to shareholders of the Company. These put provisions, if exercised, would require the Company to purchase its nephrologist partners' interests at the appraised fair value or the redemption value as defined in the specific put provision. The Company estimates the fair value of the noncontrolling interests subject to these put provisions using the income, market and asset-based approaches. The fair value derived from the methods used is evaluated and weighted, as appropriate, considering the reasonableness of the range of values indicated. Under the income approach, fair value may be determined by utilizing a weighted average cost of capital to discou
Stock-Based Compensation	Stock‑Based Compensation The Company measures and recognizes compensation expense for all share‑based payment awards based on estimated fair values at the date of grant. Determining the fair value of share‑based awards requires judgment in developing assumptions, which involve a number of variables. The Company estimates fair value by using a Monte Carlo simulation‑based approach for the portion of the option that contains both a market and performance condition and the Black‑Scholes valuation model for the portion of the option that contains a performance or a service‑based condition. The fair value of restricted stock awards is equal to the closing sale price of the Company’s common stock on the date of grant. Key inputs used to estimate the fair value of stock options include the exercise price of the award, the expected term of the option, the expected volatility of the common stock over the option’s expected term, the risk‑free interest rate over the option’s expected term and the Company’s expected annual dividend yield. Since the Company has limited history as a public company and does not yet have sufficient trading history for the Company's common stock, the expected volatility was largely estimated based on the historical equity volatility of common stock of comparable publicly traded entities over a period equal to the expected term of the stock option grants. For each of the comparable publicly traded entities, the historical equity volatility and the capital structure of the entity were used to calculate the implied stock volatility. The average implied stock volatility of the comparable publicly traded entities was then used to calculate a relevered equity volatility for the Company based on the Company’s own capital structure. Beginning in the second quarter of 2018, the Company began weighting in its own historical equity volatility to arrive at the concluded weighted-average equity volatility for the option valuation model. The comparable entities from the healthcare sector were chosen based on area of specialty. The Company will continue to apply this process until it believes a sufficient amount of historical information regarding the volatility of its own stock price becomes available. Stock‑based compensation expense for performance or service‑based stock awards is recognized over the requisite service period using the straight‑line method, which is generally the vesting period of the equity award, and is adjusted each period for actual forfeitures. The Company adopted the provision of ASU 2016-9, Compensation – Stock Compensation (Topic 718) – Improvements to Employee Share-Based Payment Accounting as of July 1, 2016. Upon early adoption, the Company elected to change its accounting policy to recognize forfeitures as they occur. The change was applied on a modified retrospective basis. See “ Note 19 - Stock-Based Compensation ” for additional discussion. For market and performance awards whose vesting is contingent upon a specified event, the Company recognizes stock compensation expense over the derived service period.
Interest Rate Swap and Cap Agreements	Interest Rate Swap and Cap Agreements The Company holds a combination of interest rate caps and a forward interest rate swap as a means of hedging its exposure to and volatility from variable‑based interest rate changes as part of its overall interest rate risk management strategy. The agreements have the economic effect of converting the LIBOR variable component of the Company’s interest rate to a fixed rate. These agreements are designated as cash flow hedges, and as a result, hedge‑effective gains or losses resulting from changes in fair values of these instruments are reported in other comprehensive income until such time as each swap or cap is realized, at which time the amounts are reclassified to other income (expense). The instruments are perfectly effective. In the event the critical terms of the agreements no longer match the Company's exposure, the Company will measure the ineffectiveness, and record those cumulative measurements in the noncash component of interest expense. Net amounts paid or received for each swap or cap that has settled has been reflected as adjustments to interest expense. These instruments do not contain credit risk contingent features.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement . This amendment modifies the disclosure requirements for assets and liabilities measured at fair value. The requirements to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for timing of transfers between levels and the valuation processes for Level 3 fair value measurements have all been removed. However, the changes in unrealized gains and losses included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period must be disclosed along with the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements (or other quantitative information if it is more reasonable). This ASU is effective for annual and interim reporting periods beginning after December 15, 2019. The Company elected to early adopt ASU 2018-13 as of January 1, 2019 and it did not have material impact on its consolidated financial statements. In February 2018, the FASB issued ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This amendment provides for the reclassification of the effect of remeasuring deferred tax balances related to items within accumulated other comprehensive income (“AOCI”) to retained earnings resulting from the Tax Cuts and Jobs Act of 2017. For public business entities, the ASU is effective for fiscal years beginning after December 15, 2018, and interim periods within those years, with early adoption permitted. Adoption of this ASU is to be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the tax laws or rates were recognized. The Company elected to early adopt ASU 2018-02 during the first quarter of 2018, and elected to reclassify the income tax effects from the Tax Cuts and Jobs Act of 2017 from AOCI to retained earnings. The reclassification decreased AOCI and increased retained earnings by $214 as of January 1, 2018. In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities , which amends and simplifies existing guidance in order to allow companies to more accurately present the economic effects of risk management activities in the financial statements. For public business entities, the ASU is effective for fiscal years beginning after December 15, 2018, and interim periods therein; however, early adoption by all entities is permitted. The Company adopted ASU 2017-12 as of January 1, 2019 and it did not have a material impact on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) – Leases: Amendments to the FASB Accounting Standards Codification . The amendments are expected to increase transparency and comparability by recognizing lease assets and liabilities of lessees on the balance sheet and disclosing key information about leasing arrangements in the financial statements. Since February 2016, the FASB has issued additional updates to serve as targeted improvements to the original standard update. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted for all organizations. The Company adopted ASU 2016-02 effective January 1, 2019 and elected not to recast comparative periods presented. The Company has engaged a professional services firm and has implemented lease accounting systems to assist in the implementation of ASU 2016-02. The Company elected the package of practical expedients permitted under the transition guidance within the new standard, which eliminates the reassessment of past leases, classification and initial direct costs. The standard will add approximately $138,000 and $149,000 in right of use assets and lease liabilities, respectively, to the Company's consolidated balance sheet as of January 1, 2019 for certain leases currently accounted for as operating leases. The difference in right of use assets and lease liabilities is driven principally by the pre-existing deferred rent balance that was reclassified as a component of the right-of-use asset upon adoption. The Company does not believe the standard will materially affect its Consolidated Statements of Operations or Consolidated Statements of Cash Flows and does not expect any impact on compliance with the Company's debt covenants, as described in “ Note 15 - Debt .” In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASC 606”), which requires companies to recognize revenue when a customer obtains control rather than when companies have transferred substantially all risks and rewards of a good or service. Since May 2014, the FASB has issued additional updates to serve as clarification to the original standard update. The standard also requires entities to enhance disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The Company adopted ASU 2014-09 on January 1, 2018, using the modified retrospective transition method. Under this method, the Company assessed the recognition of revenue for open contracts during the transition period and there was no adjustment to the opening balance of retained earnings at January 1, 2018. The comparative information has not been restated and continues to be reported under the accounting standards in effect for that period. Additionally, the Company elected the practical expedient that allows the recognition of revenue with each dialysis treatment, as that is when the Company has the right to invoice. The adoption of ASU 2014-09 did not have a material impact to the timing of revenue recognition; however, a majority of the provision for uncollectible accounts is now recognized as a direct reduction to revenues, instead of separately as a deduction to arrive at net revenue. Any amount of the provision for uncollectible accounts meeting the definition of an impaired asset is included in Patient care costs after the adoption of the new accounting standard. As a result of the Company’s election to apply ASU 2014-09 only to contracts not substantially completed as of January 1, 2018, the Company continues to maintain an allowance for doubtful accounts related to performance obligations satisfied prior to the adoption of the accounting standards. Changes to this allowance for doubtful accounts, other than write-offs of uncollectible accounts, are recorded through the provision for uncollectible accounts in accordance with prior accounting standards.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of property, plant and equipment	Property and equipment acquired as part of an acquisition are recorded at fair value and other purchases are stated at cost with depreciation calculated using the straight‑line method over their estimated useful lives as follows: Buildings 39 years Leasehold improvements Shorter of lease term or useful lives Equipment and information systems 3 to 10 years
Patient care service revenue by source	The composition of patient care service revenue by payment source is as follows: Year Ended December 31, 2018 2017 2016 Percentage of Revenues by Payor: (restated) (restated) Medicare and Medicare Advantage 67 % 61 % 54 % Commercial and other (1) 28 % 35 % 43 % Medicaid and Managed Medicaid 4 % 3 % 2 % Other (2) 1 % 1 % 1 % 100 % 100 % 100 % ________________________ (1) Principally commercial insurance companies and also includes the VA. (2) Other sources of payment of revenues include hospitals and patient self-pay. Patient self-pay revenues consist of payments received directly from patients who are either uninsured or self-pay a

Restatement of Consolidated F_2

Restatement of Consolidated Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Restated Consolidated Financial Statements	The following tables present the adjustments to previously issued consolidated financial statements. This information is presented for each impacted caption of the previously reported consolidated balance sheets as of December 31, 2017 and 2016, consolidated statement of operations and comprehensive income and consolidated statements of cash flows for the years ended December 31, 2017 and 2016. The adjustments affecting fiscal years prior to 2016 are reflected as a cumulative adjustment to the balance of retained earnings as of December 31, 2015 on the consolidated statements of changes in shareholders’ equity. Following are the restated Consolidated Balance Sheets (in thousands, except per share data): As of December 31, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 71,521 $ (10 ) f $ 71,511 Accounts receivable, net of allowance for doubtful accounts 79,662 32,980 a 112,642 Inventories 4,665 — 4,665 Prepaid expenses and other current assets 24,998 — 24,998 Income tax receivable 6,745 (6,745 ) d — Total current assets 187,591 26,225 213,816 Property and equipment, net of accumulated depreciation 168,537 — 168,537 Intangible assets, net of accumulated amortization 25,368 — 25,368 Other long-term assets 9,285 — 9,285 Goodwill 573,427 (282 ) c 573,145 Total assets $ 964,208 $ 25,943 $ 990,151 Liabilities and Equity Accounts payable $ 33,421 $ — $ 33,421 Accrued compensation and benefits 28,985 — 28,985 Accrued expenses and other current liabilities 49,963 14,612 d 64,575 Current portion of long-term debt 44,534 — 44,534 Total current liabilities 156,903 14,612 171,515 Long-term debt, less current portion 515,554 — 515,554 Income tax receivable agreement payable 7,500 — 7,500 Other long-term liabilities 14,880 — 14,880 Deferred tax liabilities 8,991 (8,569 ) d 422 Total liabilities 703,828 6,043 709,871 Commitments and contingencies Noncontrolling interests subject to put provisions 139,895 (9,457 ) b 130,438 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,034,439 issued and outstanding 193 — 193 Additional paid-in capital 67,853 31,245 b,c 99,098 Receivable from noncontrolling interests (358 ) — (358 ) Accumulated deficit (123,789 ) (12,109 ) a,b,c,d,f (135,898 ) Accumulated other comprehensive income (loss), net of tax (677 ) (214 ) d (891 ) Total American Renal Associates Holdings, Inc. deficit (56,778 ) 18,922 (37,856 ) Noncontrolling interests not subject to put provisions 177,263 10,435 b 187,698 Total equity 120,485 29,357 149,842 Total liabilities and equity $ 964,208 $ 25,943 $ 990,151 As of December 31, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 100,916 $ (11 ) f $ 100,905 Accounts receivable, net of allowance for doubtful accounts 81,127 49,084 a 130,211 Inventories 4,676 — 4,676 Prepaid expenses and other current assets 18,498 — 18,498 Income tax receivable 5,163 (5,163 ) d — Total current assets 210,380 43,910 254,290 Property and equipment, net of accumulated depreciation 170,118 — 170,118 Deferred tax assets — 10,349 d 10,349 Intangible assets, net of accumulated amortization 25,626 — 25,626 Other long-term assets 6,753 — 6,753 Goodwill 573,147 (55 ) c 573,092 Total assets $ 986,024 $ 54,204 $ 1,040,228 Liabilities and Equity Accounts payable $ 31,127 $ — $ 31,127 Accrued compensation and benefits 29,103 — 29,103 Accrued expenses and other current liabilities 45,286 17,736 d 63,022 Current portion of long-term debt 48,274 — 48,274 Total current liabilities 153,790 17,736 171,526 Long-term debt, less current portion 522,058 — 522,058 Income tax receivable agreement payable 21,200 — 21,200 Other long-term liabilities 11,670 — 11,670 Deferred tax liabilities 1,278 (1,278 ) d — Total liabilities 709,996 16,458 726,454 Commitments and contingencies Noncontrolling interests subject to put provisions 130,365 19,684 b 150,049 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 30,894,962 issued and outstanding 184 — 184 Additional paid-in capital 95,062 5,625 b,c 100,687 Receivable from noncontrolling interests (544 ) — (544 ) Accumulated deficit (128,646 ) (2,655 ) a,b,c,d,f (131,301 ) Accumulated other comprehensive income (loss), net of tax (100 ) — (100 ) Total American Renal Associates Holdings, Inc. deficit (34,044 ) 2,970 (31,074 ) Noncontrolling interests not subject to put provisions 179,707 15,092 b 194,799 Total equity 145,663 18,062 163,725 Total liabilities and equity $ 986,024 $ 54,204 $ 1,040,228 Following are the restated Consolidated Statements of Operations (in thousands, except share and per share data): For the Year Ended December 31, 2017 As Previously Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 752,510 $ (15,192 ) a $ 737,318 Provision for uncollectible accounts (7,404 ) (912 ) a (8,316 ) Net patient service operating revenues 745,106 (16,104 ) 729,002 Operating expenses: Patient care costs 482,450 651 g 483,101 General and administrative 102,598 (505 ) c,g,h 102,093 Transaction-related costs 717 — 717 Depreciation and amortization 37,634 — 37,634 Certain legal and other matters 15,249 — 15,249 Total operating expenses 638,648 146 638,794 Operating income 106,458 (16,250 ) 90,208 Interest expense, net (29,289 ) (20 ) f (29,309 ) Loss on early extinguishment of debt (526 ) — (526 ) Change in fair value of income tax receivable agreement 7,234 — 7,234 Income before income taxes 83,877 (16,270 ) 67,607 Income tax expense 8,194 1,277 d,h 9,471 Net income 75,683 (17,547 ) 58,136 Less: Net income attributable to noncontrolling interests (70,826 ) 8,093 e (62,733 ) Net income (loss) attributable to American Renal Associates Holdings, Inc. 4,857 (9,454 ) (4,597 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (12,276 ) 773 b (11,503 ) Net loss attributable to common shareholders $ (7,419 ) $ (8,681 ) $ (16,100 ) Loss per share: Basic $ (0.24 ) $ (0.52 ) Diluted $ (0.24 ) $ (0.52 ) Weighted-average number of common shares outstanding Basic 31,081,824 31,081,824 Diluted 31,081,824 31,081,824 For the Year Ended December 31, 2016 As Previously Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 756,329 $ 15,892 a $ 772,221 Provision for uncollectible accounts (6,562 ) 1,121 a (5,441 ) Net patient service operating revenues 749,767 17,013 766,780 Operating expenses: Patient care costs 452,449 4 h 452,453 General and administrative 127,631 290 f,h 127,921 Transaction-related costs 2,239 — 2,239 Depreciation and amortization 33,862 — 33,862 Certain legal and other matters 6,779 — 6,779 Total operating expenses 622,960 294 623,254 Operating income 126,807 16,719 143,526 Interest expense, net (35,933 ) (26 ) f (35,959 ) Loss on early extinguishment of debt (4,708 ) — (4,708 ) Change in fair value of income tax receivable agreement 1,286 — 1,286 Income before income taxes 87,452 16,693 104,145 Income tax (benefit) expense (753 ) 3,232 d,h 2,479 Net income 88,205 13,461 101,666 Less: Net income attributable to noncontrolling interests (88,590 ) (9,930 ) e (98,520 ) Net (loss) income attributable to American Renal Associates Holdings, Inc. (385 ) 3,531 3,146 Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (7,404 ) (2,663 ) b (10,067 ) Net loss attributable to common shareholders $ (7,789 ) $ 868 $ (6,921 ) Loss per share: Basic $ (0.28 ) $ (0.25 ) Diluted $ (0.28 ) $ (0.25 ) Weighted-average number of common shares outstanding Basic 28,116,673 28,118,673 Diluted 28,116,673 28,118,673 Cash dividends declared per share $ 1.30 $ 1.30 Following are the restated Consolidated Statements of Comprehensive Income (Loss) (in thousands): For the Year Ended December 31, 2017 As Reported Restatement Adjustments Reference As Restated Net income $ 75,683 $ (17,547 ) a,c,f $ 58,136 Unrealized loss on derivative agreements, net of tax (577 ) (214 ) d (791 ) Total comprehensive income (loss) 75,106 (17,761 ) 57,345 Less: Comprehensive income attributable to noncontrolling interests (70,826 ) 8,093 e (62,733 ) Total comprehensive income (loss) attributable to American Renal Associates Holdings, Inc. $ 4,280 $ (9,668 ) $ (5,388 ) For the Year Ended December 31, 2016 As Reported Restatement Adjustments Reference As Restated Net income $ 88,205 $ 13,461 a,f $ 101,666 Unrealized gain on derivative agreements, net of tax 401 — 401 Total comprehensive income 88,606 13,461 102,067 Less: Comprehensive income attributable to noncontrolling interests (88,590 ) (9,930 ) e (98,520 ) Total comprehensive income attributable to American Renal Associates Holdings, Inc. $ 16 $ 3,531 $ 3,547 Following are the restated Consolidated Statements of Cash Flows (in thousands): For the Year Ended December 31, 2017 As Previously Reported Restatement Adjustments Reference As Restated Operating activities Net income $ 75,683 $ (17,547 ) a,c,f $ 58,136 Adjustments to reconcile net income to cash provided by operating activities: Depreciation and amortization 37,634 — 37,634 Amortization of discounts, fees and deferred financing costs 2,031 — 2,031 Loss on early extinguishment of debt 526 — 526 Stock-based compensation 15,872 — 15,872 Premium paid for interest rate cap agreements (1,186 ) — (1,186 ) Deferred taxes 8,455 2,844 d 11,299 Change in fair value of income tax receivable agreement (7,234 ) — (7,234 ) Non-cash charge related to derivative agreements 173 — 173 Non-cash rent charges 1,044 — 1,044 Loss (gain) on disposal of assets (772 ) 745 c (27 ) Change in operating assets and liabilities, net of acquisitions: Accounts receivable 1,465 16,103 a 17,568 Inventories 11 — 11 Prepaid expenses and other current assets (7,936 ) 1,583 d (6,353 ) Other assets (1,325 ) — (1,325 ) Accounts payable 2,294 — 2,294 Accrued compensation and benefits (118 ) — (118 ) Accrued expenses and other liabilities 1,930 (3,727 ) d (1,797 ) Cash provided by operating activities 128,547 1 128,548 Investing activities Purchases of property, equipment and intangible assets (36,073 ) — (36,073 ) Proceeds from asset sales 2,325 — 2,325 Cash paid for acquisitions (1,555 ) — (1,555 ) Cash used in investing activities (35,303 ) — (35,303 ) Financing activities Net proceeds from issuance of long-term debt 267,564 — 267,564 Cash paid for financing costs (3,914 ) — (3,914 ) Proceeds on term loans, net of deferred financing costs 49,921 — 49,921 Payments on long-term debt (327,331 ) — (327,331 ) Dividends and dividend equivalents paid (8,729 ) — (8,729 ) Proceeds from exercise of stock options 2,380 — 2,380 Distribution to noncontrolling interests (79,478 ) — (79,478 ) Contributions from noncontrolling interests 6,522 — 6,522 Purchases of noncontrolling interests (29,540 ) — (29,540 ) Proceeds from sales of additional noncontrolling interests 66 — 66 Cash used in financing activities (122,539 ) — (122,539 ) Decrease in cash (29,295 ) 1 f (29,294 ) Cash at beginning of year 100,916 (11 ) f 100,905 Cash at end of year $ 71,621 $ (10 ) $ 71,611 For the Year Ended December 31, 2016 As Previously Reported Restatement Adjustments Reference As Restated Operating activities Net income $ 88,205 $ 13,461 a,f $ 101,666 Adjustments to reconcile net income to cash provided by operating activities: Depreciation and amortization 33,862 — 33,862 Amortization of discounts, fees and deferred financing costs 2,595 — 2,595 Loss on early extinguishment of debt 4,708 — 4,708 Stock-based compensation 40,285 — 40,285 Deferred taxes (14,018 ) (4,552 ) d (18,570 ) Change in fair value of income tax receivable agreement (1,286 ) — (1,286 ) Non-cash charge related to derivative agreements 473 — 473 Non-cash rent charges 2,191 — 2,191 Loss (gain) on disposal of assets 857 — 857 Change in operating assets and liabilities, net of acquisitions: Accounts receivable (4,208 ) (17,013 ) a (21,221 ) Inventories (385 ) — (385 ) Prepaid expenses and other current assets (7,226 ) 2,458 d (4,768 ) Other assets (219 ) — (219 ) Accounts payable 8,556 — 8,556 Accrued compensation and benefits 6,599 — 6,599 Accrued expenses and other liabilities 11,222 5,641 d 16,863 Cash provided by operating activities 172,211 (5 ) 172,206 Investing activities Purchases of property, equipment and intangible assets (61,432 ) — (61,432 ) Cash paid for acquisitions (4,507 ) — (4,507 ) Cash used in investing activities (65,939 ) — (65,939 ) Financing activities Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense 175,254 — 175,254 Net proceeds from issuance of long-term debt 60,000 — 60,000 Cash paid for financing costs (1,350 ) — (1,350 ) Proceeds on term loans, net of deferred financing costs 70,590 — 70,590 Payments on long-term debt (275,243 ) — (275,243 ) Dividends and dividend equivalents paid (30,241 ) — (30,241 ) Proceeds from exercise of stock options 170 — 170 Common stock repurchases for tax withholdings of net settlement equity awards (356 ) — (356 ) Distribution to noncontrolling interests (94,468 ) — (94,468 ) Contributions from noncontrolling interests 7,470 — 7,470 Purchases of noncontrolling interests (8,397 ) — (8,397 ) Proceeds from sales of additional noncontrolling interests 227 — 227 Cash used in financing activities (96,344 ) — (96,344 ) Increase in cash 9,928 (5 ) f 9,923 Cash at beginning of year 90,988 (6 ) f 90,982 Cash at end of year $ 100,916 $ (11 ) $ 100,905 The following tables present the restated unaudited quarterly condensed consolidated financial statements for each quarter-to-date and year-to-date interim period for the years ended December 31, 2018, 2017, and 2016. In the opinion of the Company's management, the unaudited condensed consolidated financial statements have been prepared on a basis consistent with the financial statements which appear elsewhere in these consolidated financial statements and include all adjustments, necessary for a fair statement of the financial position and results of operations for such unaudited periods. Historical results are not necessarily indicative of results to be expected in the future. See “ Note 3 - Restatement of Consolidated Financial Statements ” for additional information and a description of the adjustments and reclassifications in each category of restatements referenced by (a) through (h). Following are the Condensed Consolidated Balance Sheets for interim quarters ended 2018 (tables in thousands, except per share data): As of March 31, 2018 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 64,283 $ (10 ) f $ 64,273 Accounts receivable, less allowance for doubtful accounts 85,723 24,608 a 110,331 Inventories 7,642 (1,513 ) a,f 6,129 Prepaid expenses and other current assets 24,478 799 f 25,277 Income tax receivable 7,835 (7,835 ) d — Total current assets 189,961 16,049 206,010 Property and equipment, net of accumulated depreciation 168,682 — 168,682 Intangible assets, net of accumulated amortization 25,182 — 25,182 Other long-term assets 15,013 — 15,013 Goodwill 570,946 395 c 571,341 Total assets $ 969,784 $ 16,444 $ 986,228 Liabilities and Equity Accounts payable $ 40,885 $ — $ 40,885 Accrued compensation and benefits 27,160 — 27,160 Accrued expenses and other current liabilities 51,954 11,836 d 63,790 Current portion of long-term debt 45,121 — 45,121 Total current liabilities 165,120 11,836 176,956 Long-term debt, less current portion 512,822 — 512,822 Income tax receivable agreement payable 8,646 — 8,646 Other long-term liabilities 14,171 (24 ) d 14,147 Deferred tax liabilities 9,560 (9,138 ) d 422 Total liabilities 710,319 2,674 712,993 Commitments and contingencies Noncontrolling interests subject to put provisions 148,769 (8,978 ) b 139,791 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,437,507 issued and outstanding 195 — 195 Additional paid-in capital 68,632 29,611 b,c 98,243 Receivable from noncontrolling interests (515 ) — (515 ) Accumulated deficit (124,485 ) (15,001 ) a,b,c,d,f (139,486 ) Accumulated other comprehensive income (loss), net of tax 760 (214 ) d 546 Total American Renal Associates Holdings, Inc. deficit (55,413 ) 14,396 (41,017 ) Noncontrolling interests not subject to put provisions 166,109 8,352 a,b,c,d,f 174,461 Total equity 110,696 22,748 133,444 Total liabilities and equity $ 969,784 $ 16,444 $ 986,228 As of June 30, 2018 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 69,403 $ (10 ) f $ 69,393 Accounts receivable, less allowance for doubtful accounts 91,508 13,382 a 104,890 Inventories 6,535 — 6,535 Prepaid expenses and other current assets 20,338 (1,251 ) a,f 19,087 Income tax receivable 4,713 (4,713 ) d — Total current assets 192,497 7,408 199,905 Property and equipment, net of accumulated depreciation 167,621 — 167,621 Deferred tax assets — 4,596 d 4,596 Intangible assets, net of accumulated amortization 24,966 — 24,966 Other long-term assets 19,639 — 19,639 Goodwill 570,946 393 c 571,339 Total assets $ 975,669 $ 12,397 $ 988,066 Liabilities and Equity Accounts payable $ 52,849 $ — $ 52,849 Accrued compensation and benefits 30,881 — 30,881 Accrued expenses and other current liabilities 48,961 13,989 d 62,950 Current portion of long-term debt 46,660 — 46,660 Total current liabilities 179,351 13,989 193,340 Long-term debt, less current portion 509,983 — 509,983 Income tax receivable agreement payable 6,037 — 6,037 Other long-term liabilities 33,819 (3 ) d 33,816 Deferred tax liabilities 4,696 (4,696 ) d — Total liabilities 733,886 9,290 743,176 Commitments and contingencies Noncontrolling interests subject to put provisions 145,500 (4,763 ) e 140,737 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,458,837 issued and outstanding 195 — 195 Additional paid-in capital 69,170 24,169 b,c 93,339 Receivable from noncontrolling interests (477 ) — (477 ) Accumulated deficit (142,493 ) (20,652 ) a,b,c,d,f (163,145 ) Accumulated other comprehensive income (loss), net of tax 1,227 (214 ) d 1,013 Total American Renal Associates Holdings, Inc. deficit (72,378 ) 3,303 (69,075 ) Noncontrolling interests not subject to put provisions 168,661 4,567 a,b,c,d,f 173,228 Total equity 96,283 7,870 104,153 Total liabilities and equity $ 975,669 $ 12,397 $ 988,066 As of September 30, 2018 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 61,872 $ (10 ) f $ 61,862 Accounts receivable, less allowance for doubtful accounts 90,596 8,082 a 98,678 Inventories 6,382 — 6,382 Prepaid expenses and other current assets 20,608 (1,892 ) a,f 18,716 Income tax receivable 5,306 (5,306 ) d — Total current assets 184,764 874 185,638 Property and equipment, net of accumulated depreciation 168,346 — 168,346 Deferred tax assets — 4,596 d 4,596 Intangible assets, net of accumulated amortization 24,811 — 24,811 Other long-term assets 18,198 — 18,198 Goodwill 570,944 395 c 571,339 Total assets $ 967,063 $ 5,865 $ 972,928 Liabilities and Equity Accounts payable $ 54,023 $ — $ 54,023 Accrued compensation and benefits 34,658 — 34,658 Accrued expenses and other current liabilities 43,153 13,385 d 56,538 Current portion of long-term debt 47,206 — 47,206 Total current liabilities 179,040 13,385 192,425 Long-term debt, less current portion 506,750 — 506,750 Income tax receivable agreement payable 9,476 — 9,476 Other long-term liabilities 24,378 (3 ) d 24,375 Deferred tax liabilities 4,843 (4,843 ) d — Total liabilities 724,487 8,539 733,026 Commitments and contingencies Noncontrolling interests subject to put provisions 150,152 (8,916 ) b 141,236 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,514,777 issued and outstanding 195 — 195 Additional paid-in capital 65,965 27,252 b,c 93,217 Receivable from noncontrolling interests (1,340 ) — (1,340 ) Accumulated deficit (140,003 ) (23,875 ) a,b,c,d,f (163,878 ) Accumulated other comprehensive income (loss), net of tax 1,654 (214 ) d 1,440 Total American Renal Associates Holdings, Inc. deficit (73,529 ) 3,163 (70,366 ) Noncontrolling interests not subject to put provisions 165,953 3,079 a,b,c,d,f 169,032 Total equity 92,424 6,242 98,666 Total liabilities and equity $ 967,063 $ 5,865 $ 972,928 Following are the Condensed Consolidated Balance Sheets for the interim quarters ended 2017 (tables in thousands, except per share data): As of March 31, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 84,003 $ (10 ) f $ 83,993 Accounts receivable, less allowance for doubtful accounts 77,495 48,354 a 125,849 Inventories 4,648 — 4,648 Prepaid expenses and other current assets 18,217 — 18,217 Income tax receivable 9,415 (9,415 ) d — Total current assets 193,778 38,929 232,707 Property and equipment, net of accumulated depreciation 167,338 — 167,338 Deferred tax assets — 9,691 d 9,691 Intangible assets, net of accumulated amortization 25,681 — 25,681 Other long-term assets 7,472 — 7,472 Goodwill 573,147 (55 ) c 573,092 Total assets $ 967,416 $ 48,565 $ 1,015,981 Liabilities and Equity Accounts payable $ 24,605 $ — $ 24,605 Accrued compensation and benefits 26,092 — 26,092 Accrued expenses and other current liabilities 45,075 13,484 d 58,559 Current portion of long-term debt 45,559 — 45,559 Total current liabilities 141,331 13,484 154,815 Long-term debt, less current portion 520,364 — 520,364 Income tax receivable agreement payable 16,683 — 16,683 Other long-term liabilities 12,826 (3 ) d 12,823 Deferred tax liabilities 1,522 (1,522 ) d — Total liabilities 692,726 11,959 704,685 Commitments and contingencies Noncontrolling interests subject to put provisions 132,465 25,621 b 158,086 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 31,143,998 issued and outstanding 184 — 184 Additional paid-in capital 93,596 364 b,c 93,960 Receivable from noncontrolling interests (747 ) — (747 ) Accumulated deficit (129,897 ) (3,526 ) a,b,c,d,f (133,423 ) Accumulated other comprehensive income (loss), net of tax (744 ) — (744 ) Total American Renal Associates Holdings, Inc. deficit (37,608 ) (3,162 ) (40,770 ) Noncontrolling interests not subject to put provisions 179,833 14,147 a,b,c,d,f 193,980 Total equity 142,225 10,985 153,210 Total liabilities and equity $ 967,416 $ 48,565 $ 1,015,981 As of June 30, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 74,933 $ (11 ) f $ 74,922 Accounts receivable, less allowance for doubtful accounts 77,841 39,819 a 117,660 Inventories 4,960 — 4,960 Prepaid expenses and other current assets 23,150 — 23,150 Income tax receivable 10,254 (10,254 ) d — Total current assets 191,138 29,554 220,692 Property and equipment, net of accumulated depreciation 165,495 — 165,495 Deferred tax assets — 9,635 d 9,635 Intangible assets, net of accumulated amortization 25,638 — 25,638 Other long-term assets 8,885 — 8,885 Goodwill 573,147 (347 ) c 572,800 Total assets $ 964,303 $ 38,842 $ 1,003,145 Liabilities and Equity Accounts payable $ 28,184 $ — $ 28,184 Accrued compensation and benefits 28,654 — 28,654 Accrued expenses and other current liabilities 60,663 10,032 d 70,695 Current portion of long-term debt 45,711 — 45,711 Total current liabilities 163,212 10,032 173,244 Long-term debt, less current portion 516,442 — 516,442 Income tax receivable agreement payable 15,600 — 15,600 Other long-term liabilities 13,859 (3 ) d 13,856 Deferred tax liabilities 1,128 (1,128 ) d — Total liabilities 710,241 8,901 719,142 Commitments and contingencies Noncontrolling interests subject to put provisions 113,925 18,569 b 132,494 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 31,283,812 issued and outstanding 185 — 185 Additional paid-in capital 95,369 6,006 b,c 101,375 Receivable from noncontrolling interests (415 ) — (415 ) Accumulated deficit (132,003 ) (6,585 ) a,b,c,d,f (138,588 ) Accumulated other comprehensive income (loss), net of tax (1,420 ) — (1,420 ) Total American Renal Associates Holdings, Inc. deficit (38,284 ) (579 ) (38,863 ) Noncontrolling interests not subject to put provisions 178,421 11,951 a,b,c,d,f 190,372 Total equity 140,137 11,372 151,509 Total liabilities and equity $ 964,303 $ 38,842 $ 1,003,145 As of September 30, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 67,593 $ (10 ) f $ 67,583 Accounts receivable, less allowance for doubtful accounts 81,234 40,026 a 121,260 Inventories 4,672 — 4,672 Prepaid expenses and other current assets 17,133 — 17,133 Income tax receivable 8,071 (8,071 ) d — Total current assets 178,703 31,945 210,648 Property and equipment, net of accumulated depreciation 166,890 — 166,890 Deferred tax assets — 9,635 d 9,635 Intangible assets, net of accumulated amortization 25,488 — 25,488 Other long-term assets 8,636 — 8,636 Goodwill 572,702 (282 ) c 572,420 Total assets $ 952,419 $ 41,298 $ 993,717 Liabilities and Equity Accounts payable $ 33,863 $ — $ 33,863 Accrued compensation and benefits 31,767 — 31,767 Accrued expenses and other current liabilities 43,797 13,402 d 57,199 Current portion of long-term debt 44,189 — 44,189 Total current liabilities 153,616 13,402 167,018 Long-term debt, less current portion 514,846 — 514,846 Income tax receivable agreement payable 11,900 — 11,900 Other long-term liabilities 15,713 — 15,713 Deferred tax liabilities 1,110 (1,110 ) d — Total liabilities 697,185 12,292 709,477 Commitments and contingencies Noncontrolling interests subject to put provisions 110,988 22,728 b 133,716 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 31,314,217 issued and outstanding 186 — 186 Additional paid-in capital 94,158 1,201 b,c 95,359 Receivable from noncontrolling interests (484 ) — (484 ) Accumulated deficit (124,020 ) (7,180 ) a,b,c,d,f (131,200 ) Accumulated other comprehensive income (loss), net of tax (1,447 ) — (1,447 ) Total American Renal Associates Holdings, Inc. deficit (31,607 ) (5,979 ) (37,586 ) Noncontrolling interests not subject to put provisions 175,853 12,257 a,b,c,d,f 188,110 Total equity 144,246 6,278 150,524 Total liabilities and equity $ 952,419 $ 41,298 $ 993,717 Following are the Condensed Consolidated Balance Sheets for the interim quarters ended 2016 (tables in thousands, except per share data): As of March 31, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 95,965 $ (4 ) f $ 95,961 Accounts receivable, less allowance for doubtful accounts 75,831 43,492 a 119,323 Inventories 5,515 — 5,515 Prepaid expenses and other current assets 19,507 (112 ) c 19,395 Income tax receivable 2,661 (2,661 ) d — Total current assets 199,479 40,715 240,194 Property and equipment, net of accumulated depreciation 151,204 — 151,204 Intangible assets, net of accumulated amortization 25,877 — 25,877 Other long-term assets 6,574 — 6,574 Goodwill 569,315 (54 ) c 569,261 Total assets $ 952,449 $ 40,661 $ 993,110 Liabilities and Equity Accounts payable $ 23,857 $ — $ 23,857 Accrued compensation and benefits 21,496 — 21,496 Accrued expenses and other current liabilities 31,110 14,100 d 45,210 Current portion of long-term debt 27,171 — 27,171 Total current liabilities 103,634 14,100 117,734 Long-term debt, less current portion 661,369 — 661,369 Other long-term liabilities 9,927 — 9,927 Deferred tax liabilities 15,096 (7,142 ) d 7,954 Total liabilities 790,026 6,958 796,984 Commitments and contingencies Noncontrolling interests subject to put provisions 107,414 17,558 b 124,972 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 29,770,000 issued and outstanding 98 — 98 Additional paid-in capital 457 6,396 b,c 6,853 Receivable from noncontrolling interests (605 ) — (605 ) Accumulated deficit (124,505 ) (3,435 ) a,b,c,d,f (127,940 ) Accumulated other comprehensive income (loss), net of tax (401 ) — (401 ) Total American Renal Associates Holdings, Inc. deficit (124,956 ) 2,961 (121,995 ) Noncontrolling interests not subject to put provisions 179,965 13,184 a,b,c,d,f 193,149 Total equity 55,009 16,145 71,154 Total liabilities and equity $ 952,449 $ 40,661 $ 993,110 As of June 30, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 93,268 $ (6 ) f $ 93,262 Accounts receivable, less allowance for doubtful accounts 76,904 54,081 a 130,985 Inventories 4,790 — 4,790 Prepaid expenses and other current assets 14,977 (75 ) c 14,902 Income tax receivable 144 (144 ) d — Total current assets 190,083 53,856 243,939 Property and equipment, net of accumulated depreciation 160,887 — 160,887 Intangible assets, net of accumulated amortization 25,938 — 25,938 Other long-term assets 6,174 — 6,174 Goodwill 569,930 (54 ) c 569,876 Total assets $ 953,012 $ 53,802 $ 1,006,814 Liabilities and Equity Accounts payable $ 23,515 $ — $ 23,515 Accrued compensation and benefits 25,469 — 25,469 Accrued expenses and other current liabilities 45,642 11,176 d 56,818 Current portion of long-term debt 40,579 — 40,579 Total current liabilities 135,205 11,176 146,381 Long-term debt, less current portion 517,798 — 517,798 Income tax receivable agreement payable 27,800 — 27,800 Other long-term liabilities 10,361 (6 ) d 10,355 Deferred tax liabilities 7,169 785 d 7,954 Total liabilities 698,333 11,955 710,288 Commitments and contingencies Noncontrolling interests subject to put provisions 134,762 16,862 b 151,624 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 30,845,109 issued and outstanding 184 — 184 Additional paid-in capital 72,405 9,444 b,c 81,849 Receivable from noncontrolling interests (498 ) — (498 ) Accumulated deficit (133,597 ) (1,402 ) a,b,c,d,f (134,999 ) Accumulated other comprehensive income (loss), net of tax (301 ) — (301 ) Total American Renal Associates Holdings, Inc. deficit (61,807 ) 8,042 (53,765 ) Noncontrolling interests not subject to put provisions 181,724 16,943 a,b,c,d,f 198,667 Total equity 119,917 24,985 144,902 Total liabilities and equity $ 953,012 $ 53,802 $ 1,006,814 As of September 30, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 105,149 $ (11 ) f $ 105,138 Accounts receivable, less allowance for doubtful accounts 77,253 53,265 a 130,518 Inventories 4,468 — 4,468 Prepaid expenses and other current assets 12,951 (37 ) f 12,914 Income tax receivable 4,656 (4,656 ) d — Total current assets 204,477 48,561 253,038 Property and equipment, net of accumulated depreciation 165,132 — 165,132 Intangible assets, net of accumulated amortization 25,943 — 25,943 Other long-term assets 6,593 — 6,593 Goodwill 573,107 (55 ) c 573,052 Total assets $ 975,252 $ 48,506 $ 1,023,758 Liabilities and Equity Accounts payable $ 23,277 $ — $ 23,277 Accrued compensation and benefits 29,092 — 29,092 Accrued expenses and other current liabilities 54,031 5,357 d 59,388 Current portion of long-term debt 43,582 — 43,582 Total current liabilities 149,982 5,357 155,339 Long-term debt, less current portion 520,017 — 520,017 Income tax receivable agreement payable 15,670 — 15,670 Other long-term liabilities 11,262 — 11,262 Deferred tax liabilities 6,722 1,232 d 7,954 Total liabilities 703,653 6,589 710,242 Commitments and contingencies Noncontrolling interests subject to put provisions 140,336 11,580 b 151,916 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 30,868,050 issued and outstanding 184 — 184 Additional paid-in capital 69,765 14,400 b,c 84,165 Receivable from noncontrolling interests (562 ) — (562 ) Accumulated deficit (121,527 ) (699 ) a,b,c,d,f (122,226 ) Accumulated other comprehensive income (loss), net of tax (201 ) — (201 ) Total American Renal Associates Holdings, Inc. deficit (52,341 ) 13,701 (38,640 ) Noncontrolling interests not subject to put provisions 183,604 16,636 a,b,c,d,f 200,240 Total equ

Cash (Tables)

Cash (Tables)	12 Months Ended
	Dec. 31, 2018
Cash and Cash Equivalents [Abstract]
Reconciliation of Cash and Restricted Cash Reported within the Balance Sheet to the Total shown in the Statement of Cash Flows	The following table provides a reconciliation of cash and restricted cash reported within the balance sheet to the total shown in the statement of cash flows. December 31, 2018 December 31, 2017 December 31, 2016 (restated) (restated) Cash $ 55,200 $ 71,511 $ 100,905 Restricted cash included in other long-term assets 100 100 — Total cash and restricted cash shown in the statement of cash flows $ 55,300 $ 71,611 $ 100,905

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following at December 31 : 2018 2017 2016 Medicare recovery claims $ 10,622 $ 10,744 $ 9,224 Prepaid expenses and other 17,505 14,254 9,274 $ 28,127 $ 24,998 $ 18,498

Acquisitions and Divestitures (

Acquisitions and Divestitures (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Schedule of allocation of purchase price to the acquired assets	The cash consideration paid, on a combined basis for all acquisitions consummated during 2017 , was allocated based on the estimated fair value, as follows: Property and equipment $ 737 Noncompete agreements and other intangible assets 93 Goodwill 725 Cash consideration paid $ 1,555 The cash consideration paid was preliminarily based on the estimated fair value, as follows: Property and equipment $ 329 Other assets 59 Cash consideration paid $ 388 The cash consideration paid, on a combined basis for all acquisitions consummated during 2016 , was allocated based on the estimated fair value, as follows: Property and equipment $ 400 Noncompete agreements and other intangible assets 268 Goodwill 3,839 Cash consideration paid $ 4,507

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of the fair value of financial instruments	December 31, 2018 Total Level 1 Level 2 Level 3 Assets Interest rate derivative agreements (included in Prepaid expenses and other current assets) $ 836 $ — $ 836 $ — Interest rate derivative agreements (included in Other long-term assets) 395 — 395 — Total Assets $ 1,231 $ — $ 1,231 $ — Liabilities Tax Receivable Agreement Liability (included in Income tax receivable agreement payable) $ 3,700 $ — $ — $ 3,700 Total Liabilities $ 3,700 $ — $ — $ 3,700 Temporary Equity Noncontrolling interests subject to put provisions $ 129,099 $ — $ — $ 129,099 December 31, 2017 Total Level 1 Level 2 Level 3 Assets Interest rate derivative agreements (included in Prepaid expenses and other current assets) $ 46 $ — $ 46 $ — Interest rate derivative agreements (included in Other long-term assets) 255 — 255 — Total Assets $ 301 $ — $ 301 $ — Liabilities Tax Receivable Agreement Liability (included in Income tax receivable agreement payable) $ 7,500 $ — $ — $ 7,500 Interest rate derivative agreements (included in Accrued expense and other current liabilities) 403 — 403 — Interest rate derivative agreements (included in Other long-term liabilities) 198 — 198 — Total Liabilities $ 8,101 $ — $ 601 $ 7,500 Temporary Equity Noncontrolling interests subject to put provisions(1) $ 130,438 $ — $ — $ 130,438
Fair value rollforward for the tax receivable agreement liability, which is classified as a Level 3 financial instrument	The following table provides the fair value rollforward for the TRA liability, which is classified as a Level 3 financial instrument. Balance at January 1, 2016 — Initial fair value as of April 20, 2016 23,400 Options exercised and dividend equivalent payment vesting (914 ) Total realized/unrealized gains: Included in earnings and reported as Change in fair value of income tax receivable agreement $ (1,286 ) Balance at December 31, 2016 $ 21,200 Options exercised and dividend equivalent payment vesting (6,466 ) Total realized/unrealized gains: Included in earnings and reported as Change in fair value of income tax receivable agreement (7,234 ) Balance at December 31, 2017 $ 7,500 Options exercised and dividend equivalent payment vesting (1,127 ) Total realized/unrealized gains: Included in earnings and reported as Change in fair value of income tax receivable agreement (2,673 ) Balance at December 31, 2018 $ 3,700 The carrying amounts repo

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Schedule of property and equipment	Property and equipment consist of the following at December 31 : 2018 2017 2016 Land $ 2,030 $ 2,030 $ 2,203 Buildings and improvements 8,197 2,904 3,425 Leasehold improvements 201,445 178,569 154,783 Equipment and information systems 162,750 145,514 125,813 Construction in progress 5,549 6,910 5,136 379,971 335,927 291,360 Less accumulated depreciation (199,703 ) (167,390 ) (121,242 ) $ 180,268 $ 168,537 $ 170,118

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of intangible assets	Intangible assets consist of the following at December 31 : 2018 2017 2016 Noncompete agreements $ 24,370 $ 24,380 $ 24,928 Other intangible assets 3,130 3,073 2,853 27,500 27,453 27,781 Less accumulated amortization (24,206 ) (23,419 ) (23,489 ) Net intangible assets subject to amortization 3,294 4,034 4,292 Indefinite‑lived trademarks and trade name 21,334 21,334 21,334 $ 24,628 $ 25,368 $ 25,626
Schedule of estimated annual amortization expense	The estimated annual amortization expense related to amortizable intangible assets is as follows for the years ending December 31 : 2019 $ 747 2020 665 2021 615 2022 470 2023 220 Thereafter 577 $ 3,294
Schedule of changes in value of goodwill	Changes in the value of goodwill: Balance at January 1, 2016, as restated $ 569,264 Acquisitions 3,839 Subsequent adjustment for prior year acquisition (11 ) Balance at December 31, 2016, as restated $ 573,092 Acquisitions 725 Divestitures (672 ) Balance as of December 31, 2017, as restated $ 573,145 Divestitures (1,806 ) Balance at December 31, 2018 $ 571,339

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Accounts Payable and Accrued Liabilities, Current [Abstract]
Summary of accrued compensation and benefits	Accrued compensation and benefits consist of the following at December 31 : 2018 2017 2016 Accrued compensation $ 22,480 $ 17,987 $ 18,077 Accrued vacation pay 12,107 10,998 11,026 $ 34,587 $ 28,985 $ 29,103
Summary of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consist of the following at December 31 : 2018 2017 2016 (restated) (restated) Due to payors $ 26,659 $ 28,935 $ 32,902 Income tax payable 13,618 14,654 17,851 Other 13,198 20,986 12,269 Accrued Settlement (Note 22) 7,641 — — $ 61,116 $ 64,575 $ 63,022

Noncontrolling Interests Subj_2

Noncontrolling Interests Subject to Put Provisions (Tables)	12 Months Ended
	Dec. 31, 2018
Temporary Equity Disclosure [Abstract]
Schedules of Noncontrolling Interests Subject to Put Provisions	The Company's computation of the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests as of December 31, 2018 , 2017 , and 2016 is set forth below. December 31, 2018 December 31, 2017 December 31, 2016 (restated) (restated) Redemption value $ 11,221 $ 12,283 $ 20,491 Estimated fair values for accounting purposes 2,672 5,970 10,424 Difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests $ 8,549 $ 6,313 $ 10,067 In addition, the tables below set forth a reconciliation of noncontrolling interests subject to put provisions. December 31, 2018 December 31, 2017 December 31, 2016 (restated) (restated) Noncontrolling interest subject to put provisions - estimated fair values $ 120,550 $ 124,125 $ 139,982 Difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests 8,549 6,313 10,067 Noncontrolling interests subject to put provisions - maximum redemption value $ 129,099 $ 130,438 $ 150,049 Year ended December 31, 2018 Year ended December 31, 2017 Year ended December 31, 2016 (restated) (restated) Change in estimated fair values for accounting purposes $ (9,963 ) $ (1,886 ) $ 17,415 Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests 2,566 11,503 10,067 Total change in fair value of noncontrolling interests subject to put provisions - maximum redemption $ (7,397 ) $ 9,617 $ 27,482

Changes in Ownership Interest_2

Changes in Ownership Interest in Consolidated Subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2018
CHANGES IN OWNERSHIP INTEREST IN CONSOLIDATED SUBSIDIARIES
Schedule of effect of changes in Company's ownership interest on Company's equity	The effects of changes in the Company’s ownership interests in its consolidated subsidiaries on the Company’s equity are as follows: Year ended December 31, 2018 2017 2016 (restated) (restated) Net (loss) income attributable to American Renal Associates Holdings, Inc. $ (28,767 ) $ (4,597 ) $ 3,146 (Decrease) increase in paid-in capital for the sales of noncontrolling interest (891 ) 231 99 Decrease in paid-in capital for the purchase of noncontrolling interest and adjustments to ownership interest (6,645 ) (7,566 ) (7,680 ) Net transfers to noncontrolling interests (7,536 ) (7,335 ) (7,581 ) Net loss attributable to American Renal Associates Holdings, Inc., net of transfers to noncontrolling interests $ (36,303 ) $ (11,932 ) $ (4,435 )

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Instruments [Abstract]
Schedule of long-term debt	Long‑term debt consists of the following at December 31 : 2018 2017 2016 2017 Credit Agreement - Term B Loan Facility $ 433,400 $ 437,800 $ 433,758 2017 Credit Agreement - Revolving Credit Facility 5,500 — — Assigned Clinic Loans due to Term Loan Holdings(1) 5,078 11,082 19,768 Other Term Loans(2) 113,866 114,536 98,735 Other Lines of Credit(3) 1,849 3,600 19,360 Capital Lease Obligations(4) 6,706 — — Other(5) 2,040 2,601 3,041 568,439 569,619 574,662 Less: discounts and fees, net of accumulated amortization (8,073 ) (9,531 ) (4,330 ) Less: current maturities (42,855 ) (44,534 ) (48,274 ) $ 517,511 $ 515,554 $ 522,058 (1) See “ Note 4 - Initial Public Offering ” and “ Note 20 - Related Party Transactions .” (2) Principal and interest is payable monthly at rates between 3.31% and 7.98% over varying periods through June 2026. (3) The interest on the lines of credit is payable monthly at rates between 4.13% and 5.13% and convert to term loans at various maturity dates through August 2022. (4) Capital lease obligations expiring in various years through 2033. (5) Principal and interest of the other corporate debt is payable monthly at a rate of 4.07% maturing in April 2022. Scheduled maturities of long‑term debt as of December 31, 2018 are as fo
Schedule of maturities of long-term debt	Scheduled maturities of long‑term debt as of December 31, 2018 are as follows: 2019 $ 43,022 2020 35,761 2021 26,461 2022 23,956 2023 15,128 Thereafter 424,111 $ 568,439

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Schedule of future minimum lease payments	Future minimum lease payments under noncancelable operating leases, net of sublease receipts and capital leases as of December 31, 2018 , are as follows: Year Ended December 31, Operating Leases Less: Sublease Receipts Net Operating Leases Capital Leases 2019 $ 31,311 $ 1,537 $ 29,774 $ 876 2020 29,608 1,551 28,057 930 2021 27,597 1,572 26,025 940 2022 25,132 1,592 23,540 950 2023 20,363 1,117 19,246 963 Thereafter 61,085 3,175 57,910 6,286 Total minimum lease payments $ 195,096 $ 10,544 $ 184,552 $ 10,945 Less: amount representing interest 4,239 Present value of net minimum capital lease payments $ 6,706 Less: current installments of obligations under capital leases 302 Long-term capital lease obligation $ 6,404

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of provision (benefit) for income taxes	The provision for income taxes consisted of the following for the years ended December 31 : 2018 2017 2016 (restated) (restated) Current: Federal $ (112 ) $ (2,000 ) $ 17,432 State 657 173 3,617 $ 545 $ (1,827 ) $ 21,049 Deferred: Federal $ 1,348 $ 9,435 $ (15,873 ) State 1,003 1,863 (2,697 ) $ 2,351 $ 11,298 $ (18,570 ) Total provision for income taxes $ 2,896 $ 9,471 $ 2,479
Schedule of significant components of deferred tax assets and liabilities	The significant components of deferred tax assets and liabilities are as follows at December 31 : 2018 2017 2016 (restated) (restated) Net operating loss and contribution carryforwards $ 5,542 $ 5,541 $ 7,092 Legal settlement (Note 23) 5,065 — — Accrued expenses 1,484 1,115 1,519 Stock-based compensation 9,417 9,708 16,568 Interest limitation 2,189 — — Other 165 165 250 Interest rate swap — 379 66 Deferred tax assets: 23,862 16,908 25,495 Valuation allowance (12,420 ) (5,414 ) — Total deferred tax assets 11,442 11,494 25,495 Investment in joint ventures (9,784 ) (7,254 ) (8,039 ) Goodwill and intangible amortization (3,400 ) (3,331 ) (4,943 ) Depreciation (1,378 ) (1,293 ) (2,054 ) Other (49 ) (38 ) (110 ) Total deferred tax liabilities (14,611 ) (11,916 ) (15,146 ) Net deferred tax (liabilities) assets $ (3,169 ) $ (422 ) $ 10,349
Summary of reconciliation of the federal statutory rate to the Company’s effective tax rate	A reconciliation of the federal statutory rate to the Company’s effective tax rate is as follows for the years ended December 31 : 2018 2017 2016 (restated) (restated) Income tax provision at federal statutory rate 21 % 35 % 35 % Increase (decrease) in tax resulting from: State taxes, net of federal benefit (2.9 )% 0.6 % 0.9 % Noncontrolling interests in passthrough entities (44.0 )% (32.3 )% (33.4 )% Valuation allowance 33.0 % 8.7 % — % Other permanent items, net 4.8 % 2.0 % (0.1 )% Effective income tax rate 11.9 % 14.0 % 2.4 %
Summary of gross amounts of unrecognized tax benefits	The following table summarizes the gross amounts of unrecognized tax benefits without regard to reduction in tax liabilities or additions to deferred tax assets and liabilities if such unrecognized tax benefits were settled: 2018 2017 2016 January 1 $ 21,077 $ 25,062 $ 15,833 Increase due to current year tax positions — — 9,229 Decrease due to prior year tax positions (4,109 ) (3,985 ) — December 31 $ 16,968 $ 21,077 $ 25,062

Loss Per Share (Tables)

Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Schedule of basic and diluted earnings (loss) per share	Year ended December 31, 2018 2017 2016 (restated) (restated) Basic and Diluted Net (loss) income attributable to American Renal Associates Holdings, Inc. $ (28,767 ) $ (4,597 ) $ 3,146 Change in the difference between the redemption values and estimated fair values for accounting purposes of the related noncontrolling interests (2,566 ) (11,503 ) (10,067 ) Net loss attributable to common shareholders (31,333 ) (16,100 ) (6,921 ) Weighted‑average common shares outstanding 31,965,844 31,081,824 28,118,673 Weighted‑average common shares outstanding, assuming dilution 31,965,844 31,081,824 28,118,673 Loss per share, basic and diluted $ (0.98 ) $ (0.52 ) $ (0.25 ) Outstanding options excluded as impact would be antidilutive 3,442,048 1,894,340 572,097

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Schedule of stock-based compensation expense	The following table presents the stock‑based compensation expense and related income tax benefit included in the Company’s consolidated statements of operations for the years ended December 31 : 2018 2017 2016 Patient care costs $ 714 $ 2,773 $ 5,720 General and administrative 5,007 13,099 34,578 Total stock‑based compensation $ 5,721 $ 15,872 $ 40,298 Income tax benefit $ 1,493 $ 6,349 $ 16,119
Schedule of assumptions used for options granted to acquire Common Stock and the fair value at the date of grant	The weighted‑average assumptions used in the option valuation models for awards granted in 2018 , 2017 and 2016 are as follows. 2018 2017 2016 Expected volatility(1) 30 - 35% 30 - 35% 25 % Expected term in years(2) 6.0 6.0 6.0 - 6.5 Risk-free interest rate(3) 2.74 - 2.99% 1.92 - 2.26% 1.20 - 1.58% Expected annual dividend yield(4) — % — % — % Weighted-average grant-date fair value $ 7.14 $ 5.52 $ 6.24 (1) Since the Company does not have sufficient history as a public company and does not have sufficient trading history for its common stock, the expected volatility was largely estimated based on the historical equity volatility of common stock of comparable publicly traded entities over a period equal to the expected term of the stock option grants. For each of the comparable publicly traded entities, the historical equity volatility and the capital structure of the entity were used to calculate the implied stock volatility. The average implied stock volatility of the comparable publicly traded entities was then used to calculate a relevered equity volatility for the Company based on the Company’s own capital structure. In the first quarter of 2018, the Company utilized the relevered equity volatility based on the comparable publicly traded entities for the Company and beginning in the second quarter of 2018, the Company began weighting in its own historical equity volatility to arrive at the concluded weighted-average equity volatility for the option valuation model. The comparable entities from the healthcare sector were chosen based on area of specialty. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of the Company's own stock price becomes available. (2) Expected term of 6.0 years for a service‑based option is based on the “short‑cut method” as prescribed by Securities and Exchange Commission’s Staff Accounting Bulletin No. 110. (3) The risk‑free interest rate is based on the yield of zero‑coupon U.S. Treasury securities for a period that is commensurate with the expected option term at the time of grant. (4) Expected dividend yield is based on management’s expectations.
Schedule of information concerning options activity for options to acquire Common Stock	The following table summarizes the combined stock option activity under the Company’s stock option plans for the year ended December 31, 2018 : Number of Shares Weighted - Weighted - average Aggregate Options outstanding as of January 1, 2018 5,280,261 $ 11.79 Granted 296,286 19.32 Exercised (348,442 ) 5.17 Forfeited/Cancelled (216,914 ) 16.50 Options outstanding as of December 31, 2018 5,011,191 $ 12.38 4.99 $ 17,056 Vested and expected to vest as of December 31, 2018 5,011,191 $ 12.38 4.99 $ 17,056 Exercisable as of December 31, 2018 3,172,792 $ 8.29 3.98 $ 17,056
Schedule of restricted stock award activity	A summary of restricted stock award activity is as follows: Number of Shares Weighted - average grant date fair value Unvested as of January 1, 2018 252,307 $ 16.70 Granted 359,691 22.18 Vested (100,553 ) 16.91 Forfeited/Cancelled (70,382 ) 19.48 Unvested as of December 31, 2018 441,063 $ 20.68

Subsequent Events (Tables)

Subsequent Events (Tables)	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Schedule of allocation of cash consideration paid	The consideration transferred, on a combined basis for all acquisitions consummated during 2019 through the date of issuance of these financial statements, was as follows: Cash $ 6,590 Equity interests 4,655 Fair value of total consideration transferred $ 11,245 The amounts recognized as of the acquisition date, on a combined basis for all acquisitions consummated during 2019 through the date of issuance of these financial statements, for each major class of assets acquired and liabilities assumed were allocated preliminarily based on the estimated fair value, as follows: Property and equipment $ 1,657 Noncompete agreements 660 Goodwill 8,683 Other assets 245 Total consideration paid $ 11,245

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	Three Months Ended (in thousands, except for share data) December 31, 2018 September 30, 2018 June 30, 2018 March 31, 2018 December 31, 2017 September 30, 2017 June 30, 2017 March 31, 2017 (restated) (restated) (restated) (restated) (restated) (restated) (restated) Patient service operating revenues $ 207,806 $ 205,719 $ 205,952 $ 186,299 $ 190,509 $ 190,670 $ 177,890 $ 178,249 Net patient service operating revenues $ 207,806 $ 205,719 $ 205,952 $ 186,299 $ 187,331 $ 187,918 $ 177,459 $ 176,294 Operating Income (loss) $ 22,949 $ 24,110 $ (4,310 ) $ 12,573 $ 27,033 $ 33,224 $ 18,277 $ 11,674 Income (loss) before income taxes $ 19,590 $ 12,388 $ (10,710 ) $ 4,095 $ 21,549 $ 29,554 $ 7,922 $ 8,582 Net income (loss) attributable to American Renal Associates Holdings, Inc. $ (572 ) $ (734 ) $ (23,659 ) $ (3,802 ) $ (4,898 ) $ 7,496 $ (5,073 ) $ (2,122 ) Basic (loss) income per share attributable to American Renal Associates Holdings, Inc. $ (0.06 ) $ (0.04 ) $ (0.78 ) $ (0.10 ) $ (0.12 ) $ 0.26 $ (0.26 ) $ (0.41 ) Diluted (loss) income per share attributable to American Renal Associates Holdings, Inc. $ (0.06 ) $ (0.04 ) $ (0.78 ) $ (0.10 ) $ (0.12 ) $ 0.24 $ (0.26 ) $ (0.41 )
Restated Consolidated Financial Statements	The following tables present the adjustments to previously issued consolidated financial statements. This information is presented for each impacted caption of the previously reported consolidated balance sheets as of December 31, 2017 and 2016, consolidated statement of operations and comprehensive income and consolidated statements of cash flows for the years ended December 31, 2017 and 2016. The adjustments affecting fiscal years prior to 2016 are reflected as a cumulative adjustment to the balance of retained earnings as of December 31, 2015 on the consolidated statements of changes in shareholders’ equity. Following are the restated Consolidated Balance Sheets (in thousands, except per share data): As of December 31, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 71,521 $ (10 ) f $ 71,511 Accounts receivable, net of allowance for doubtful accounts 79,662 32,980 a 112,642 Inventories 4,665 — 4,665 Prepaid expenses and other current assets 24,998 — 24,998 Income tax receivable 6,745 (6,745 ) d — Total current assets 187,591 26,225 213,816 Property and equipment, net of accumulated depreciation 168,537 — 168,537 Intangible assets, net of accumulated amortization 25,368 — 25,368 Other long-term assets 9,285 — 9,285 Goodwill 573,427 (282 ) c 573,145 Total assets $ 964,208 $ 25,943 $ 990,151 Liabilities and Equity Accounts payable $ 33,421 $ — $ 33,421 Accrued compensation and benefits 28,985 — 28,985 Accrued expenses and other current liabilities 49,963 14,612 d 64,575 Current portion of long-term debt 44,534 — 44,534 Total current liabilities 156,903 14,612 171,515 Long-term debt, less current portion 515,554 — 515,554 Income tax receivable agreement payable 7,500 — 7,500 Other long-term liabilities 14,880 — 14,880 Deferred tax liabilities 8,991 (8,569 ) d 422 Total liabilities 703,828 6,043 709,871 Commitments and contingencies Noncontrolling interests subject to put provisions 139,895 (9,457 ) b 130,438 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,034,439 issued and outstanding 193 — 193 Additional paid-in capital 67,853 31,245 b,c 99,098 Receivable from noncontrolling interests (358 ) — (358 ) Accumulated deficit (123,789 ) (12,109 ) a,b,c,d,f (135,898 ) Accumulated other comprehensive income (loss), net of tax (677 ) (214 ) d (891 ) Total American Renal Associates Holdings, Inc. deficit (56,778 ) 18,922 (37,856 ) Noncontrolling interests not subject to put provisions 177,263 10,435 b 187,698 Total equity 120,485 29,357 149,842 Total liabilities and equity $ 964,208 $ 25,943 $ 990,151 As of December 31, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 100,916 $ (11 ) f $ 100,905 Accounts receivable, net of allowance for doubtful accounts 81,127 49,084 a 130,211 Inventories 4,676 — 4,676 Prepaid expenses and other current assets 18,498 — 18,498 Income tax receivable 5,163 (5,163 ) d — Total current assets 210,380 43,910 254,290 Property and equipment, net of accumulated depreciation 170,118 — 170,118 Deferred tax assets — 10,349 d 10,349 Intangible assets, net of accumulated amortization 25,626 — 25,626 Other long-term assets 6,753 — 6,753 Goodwill 573,147 (55 ) c 573,092 Total assets $ 986,024 $ 54,204 $ 1,040,228 Liabilities and Equity Accounts payable $ 31,127 $ — $ 31,127 Accrued compensation and benefits 29,103 — 29,103 Accrued expenses and other current liabilities 45,286 17,736 d 63,022 Current portion of long-term debt 48,274 — 48,274 Total current liabilities 153,790 17,736 171,526 Long-term debt, less current portion 522,058 — 522,058 Income tax receivable agreement payable 21,200 — 21,200 Other long-term liabilities 11,670 — 11,670 Deferred tax liabilities 1,278 (1,278 ) d — Total liabilities 709,996 16,458 726,454 Commitments and contingencies Noncontrolling interests subject to put provisions 130,365 19,684 b 150,049 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 30,894,962 issued and outstanding 184 — 184 Additional paid-in capital 95,062 5,625 b,c 100,687 Receivable from noncontrolling interests (544 ) — (544 ) Accumulated deficit (128,646 ) (2,655 ) a,b,c,d,f (131,301 ) Accumulated other comprehensive income (loss), net of tax (100 ) — (100 ) Total American Renal Associates Holdings, Inc. deficit (34,044 ) 2,970 (31,074 ) Noncontrolling interests not subject to put provisions 179,707 15,092 b 194,799 Total equity 145,663 18,062 163,725 Total liabilities and equity $ 986,024 $ 54,204 $ 1,040,228 Following are the restated Consolidated Statements of Operations (in thousands, except share and per share data): For the Year Ended December 31, 2017 As Previously Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 752,510 $ (15,192 ) a $ 737,318 Provision for uncollectible accounts (7,404 ) (912 ) a (8,316 ) Net patient service operating revenues 745,106 (16,104 ) 729,002 Operating expenses: Patient care costs 482,450 651 g 483,101 General and administrative 102,598 (505 ) c,g,h 102,093 Transaction-related costs 717 — 717 Depreciation and amortization 37,634 — 37,634 Certain legal and other matters 15,249 — 15,249 Total operating expenses 638,648 146 638,794 Operating income 106,458 (16,250 ) 90,208 Interest expense, net (29,289 ) (20 ) f (29,309 ) Loss on early extinguishment of debt (526 ) — (526 ) Change in fair value of income tax receivable agreement 7,234 — 7,234 Income before income taxes 83,877 (16,270 ) 67,607 Income tax expense 8,194 1,277 d,h 9,471 Net income 75,683 (17,547 ) 58,136 Less: Net income attributable to noncontrolling interests (70,826 ) 8,093 e (62,733 ) Net income (loss) attributable to American Renal Associates Holdings, Inc. 4,857 (9,454 ) (4,597 ) Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (12,276 ) 773 b (11,503 ) Net loss attributable to common shareholders $ (7,419 ) $ (8,681 ) $ (16,100 ) Loss per share: Basic $ (0.24 ) $ (0.52 ) Diluted $ (0.24 ) $ (0.52 ) Weighted-average number of common shares outstanding Basic 31,081,824 31,081,824 Diluted 31,081,824 31,081,824 For the Year Ended December 31, 2016 As Previously Reported Restatement Adjustments Reference As Restated Patient service operating revenues $ 756,329 $ 15,892 a $ 772,221 Provision for uncollectible accounts (6,562 ) 1,121 a (5,441 ) Net patient service operating revenues 749,767 17,013 766,780 Operating expenses: Patient care costs 452,449 4 h 452,453 General and administrative 127,631 290 f,h 127,921 Transaction-related costs 2,239 — 2,239 Depreciation and amortization 33,862 — 33,862 Certain legal and other matters 6,779 — 6,779 Total operating expenses 622,960 294 623,254 Operating income 126,807 16,719 143,526 Interest expense, net (35,933 ) (26 ) f (35,959 ) Loss on early extinguishment of debt (4,708 ) — (4,708 ) Change in fair value of income tax receivable agreement 1,286 — 1,286 Income before income taxes 87,452 16,693 104,145 Income tax (benefit) expense (753 ) 3,232 d,h 2,479 Net income 88,205 13,461 101,666 Less: Net income attributable to noncontrolling interests (88,590 ) (9,930 ) e (98,520 ) Net (loss) income attributable to American Renal Associates Holdings, Inc. (385 ) 3,531 3,146 Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests (7,404 ) (2,663 ) b (10,067 ) Net loss attributable to common shareholders $ (7,789 ) $ 868 $ (6,921 ) Loss per share: Basic $ (0.28 ) $ (0.25 ) Diluted $ (0.28 ) $ (0.25 ) Weighted-average number of common shares outstanding Basic 28,116,673 28,118,673 Diluted 28,116,673 28,118,673 Cash dividends declared per share $ 1.30 $ 1.30 Following are the restated Consolidated Statements of Comprehensive Income (Loss) (in thousands): For the Year Ended December 31, 2017 As Reported Restatement Adjustments Reference As Restated Net income $ 75,683 $ (17,547 ) a,c,f $ 58,136 Unrealized loss on derivative agreements, net of tax (577 ) (214 ) d (791 ) Total comprehensive income (loss) 75,106 (17,761 ) 57,345 Less: Comprehensive income attributable to noncontrolling interests (70,826 ) 8,093 e (62,733 ) Total comprehensive income (loss) attributable to American Renal Associates Holdings, Inc. $ 4,280 $ (9,668 ) $ (5,388 ) For the Year Ended December 31, 2016 As Reported Restatement Adjustments Reference As Restated Net income $ 88,205 $ 13,461 a,f $ 101,666 Unrealized gain on derivative agreements, net of tax 401 — 401 Total comprehensive income 88,606 13,461 102,067 Less: Comprehensive income attributable to noncontrolling interests (88,590 ) (9,930 ) e (98,520 ) Total comprehensive income attributable to American Renal Associates Holdings, Inc. $ 16 $ 3,531 $ 3,547 Following are the restated Consolidated Statements of Cash Flows (in thousands): For the Year Ended December 31, 2017 As Previously Reported Restatement Adjustments Reference As Restated Operating activities Net income $ 75,683 $ (17,547 ) a,c,f $ 58,136 Adjustments to reconcile net income to cash provided by operating activities: Depreciation and amortization 37,634 — 37,634 Amortization of discounts, fees and deferred financing costs 2,031 — 2,031 Loss on early extinguishment of debt 526 — 526 Stock-based compensation 15,872 — 15,872 Premium paid for interest rate cap agreements (1,186 ) — (1,186 ) Deferred taxes 8,455 2,844 d 11,299 Change in fair value of income tax receivable agreement (7,234 ) — (7,234 ) Non-cash charge related to derivative agreements 173 — 173 Non-cash rent charges 1,044 — 1,044 Loss (gain) on disposal of assets (772 ) 745 c (27 ) Change in operating assets and liabilities, net of acquisitions: Accounts receivable 1,465 16,103 a 17,568 Inventories 11 — 11 Prepaid expenses and other current assets (7,936 ) 1,583 d (6,353 ) Other assets (1,325 ) — (1,325 ) Accounts payable 2,294 — 2,294 Accrued compensation and benefits (118 ) — (118 ) Accrued expenses and other liabilities 1,930 (3,727 ) d (1,797 ) Cash provided by operating activities 128,547 1 128,548 Investing activities Purchases of property, equipment and intangible assets (36,073 ) — (36,073 ) Proceeds from asset sales 2,325 — 2,325 Cash paid for acquisitions (1,555 ) — (1,555 ) Cash used in investing activities (35,303 ) — (35,303 ) Financing activities Net proceeds from issuance of long-term debt 267,564 — 267,564 Cash paid for financing costs (3,914 ) — (3,914 ) Proceeds on term loans, net of deferred financing costs 49,921 — 49,921 Payments on long-term debt (327,331 ) — (327,331 ) Dividends and dividend equivalents paid (8,729 ) — (8,729 ) Proceeds from exercise of stock options 2,380 — 2,380 Distribution to noncontrolling interests (79,478 ) — (79,478 ) Contributions from noncontrolling interests 6,522 — 6,522 Purchases of noncontrolling interests (29,540 ) — (29,540 ) Proceeds from sales of additional noncontrolling interests 66 — 66 Cash used in financing activities (122,539 ) — (122,539 ) Decrease in cash (29,295 ) 1 f (29,294 ) Cash at beginning of year 100,916 (11 ) f 100,905 Cash at end of year $ 71,621 $ (10 ) $ 71,611 For the Year Ended December 31, 2016 As Previously Reported Restatement Adjustments Reference As Restated Operating activities Net income $ 88,205 $ 13,461 a,f $ 101,666 Adjustments to reconcile net income to cash provided by operating activities: Depreciation and amortization 33,862 — 33,862 Amortization of discounts, fees and deferred financing costs 2,595 — 2,595 Loss on early extinguishment of debt 4,708 — 4,708 Stock-based compensation 40,285 — 40,285 Deferred taxes (14,018 ) (4,552 ) d (18,570 ) Change in fair value of income tax receivable agreement (1,286 ) — (1,286 ) Non-cash charge related to derivative agreements 473 — 473 Non-cash rent charges 2,191 — 2,191 Loss (gain) on disposal of assets 857 — 857 Change in operating assets and liabilities, net of acquisitions: Accounts receivable (4,208 ) (17,013 ) a (21,221 ) Inventories (385 ) — (385 ) Prepaid expenses and other current assets (7,226 ) 2,458 d (4,768 ) Other assets (219 ) — (219 ) Accounts payable 8,556 — 8,556 Accrued compensation and benefits 6,599 — 6,599 Accrued expenses and other liabilities 11,222 5,641 d 16,863 Cash provided by operating activities 172,211 (5 ) 172,206 Investing activities Purchases of property, equipment and intangible assets (61,432 ) — (61,432 ) Cash paid for acquisitions (4,507 ) — (4,507 ) Cash used in investing activities (65,939 ) — (65,939 ) Financing activities Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense 175,254 — 175,254 Net proceeds from issuance of long-term debt 60,000 — 60,000 Cash paid for financing costs (1,350 ) — (1,350 ) Proceeds on term loans, net of deferred financing costs 70,590 — 70,590 Payments on long-term debt (275,243 ) — (275,243 ) Dividends and dividend equivalents paid (30,241 ) — (30,241 ) Proceeds from exercise of stock options 170 — 170 Common stock repurchases for tax withholdings of net settlement equity awards (356 ) — (356 ) Distribution to noncontrolling interests (94,468 ) — (94,468 ) Contributions from noncontrolling interests 7,470 — 7,470 Purchases of noncontrolling interests (8,397 ) — (8,397 ) Proceeds from sales of additional noncontrolling interests 227 — 227 Cash used in financing activities (96,344 ) — (96,344 ) Increase in cash 9,928 (5 ) f 9,923 Cash at beginning of year 90,988 (6 ) f 90,982 Cash at end of year $ 100,916 $ (11 ) $ 100,905 The following tables present the restated unaudited quarterly condensed consolidated financial statements for each quarter-to-date and year-to-date interim period for the years ended December 31, 2018, 2017, and 2016. In the opinion of the Company's management, the unaudited condensed consolidated financial statements have been prepared on a basis consistent with the financial statements which appear elsewhere in these consolidated financial statements and include all adjustments, necessary for a fair statement of the financial position and results of operations for such unaudited periods. Historical results are not necessarily indicative of results to be expected in the future. See “ Note 3 - Restatement of Consolidated Financial Statements ” for additional information and a description of the adjustments and reclassifications in each category of restatements referenced by (a) through (h). Following are the Condensed Consolidated Balance Sheets for interim quarters ended 2018 (tables in thousands, except per share data): As of March 31, 2018 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 64,283 $ (10 ) f $ 64,273 Accounts receivable, less allowance for doubtful accounts 85,723 24,608 a 110,331 Inventories 7,642 (1,513 ) a,f 6,129 Prepaid expenses and other current assets 24,478 799 f 25,277 Income tax receivable 7,835 (7,835 ) d — Total current assets 189,961 16,049 206,010 Property and equipment, net of accumulated depreciation 168,682 — 168,682 Intangible assets, net of accumulated amortization 25,182 — 25,182 Other long-term assets 15,013 — 15,013 Goodwill 570,946 395 c 571,341 Total assets $ 969,784 $ 16,444 $ 986,228 Liabilities and Equity Accounts payable $ 40,885 $ — $ 40,885 Accrued compensation and benefits 27,160 — 27,160 Accrued expenses and other current liabilities 51,954 11,836 d 63,790 Current portion of long-term debt 45,121 — 45,121 Total current liabilities 165,120 11,836 176,956 Long-term debt, less current portion 512,822 — 512,822 Income tax receivable agreement payable 8,646 — 8,646 Other long-term liabilities 14,171 (24 ) d 14,147 Deferred tax liabilities 9,560 (9,138 ) d 422 Total liabilities 710,319 2,674 712,993 Commitments and contingencies Noncontrolling interests subject to put provisions 148,769 (8,978 ) b 139,791 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,437,507 issued and outstanding 195 — 195 Additional paid-in capital 68,632 29,611 b,c 98,243 Receivable from noncontrolling interests (515 ) — (515 ) Accumulated deficit (124,485 ) (15,001 ) a,b,c,d,f (139,486 ) Accumulated other comprehensive income (loss), net of tax 760 (214 ) d 546 Total American Renal Associates Holdings, Inc. deficit (55,413 ) 14,396 (41,017 ) Noncontrolling interests not subject to put provisions 166,109 8,352 a,b,c,d,f 174,461 Total equity 110,696 22,748 133,444 Total liabilities and equity $ 969,784 $ 16,444 $ 986,228 As of June 30, 2018 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 69,403 $ (10 ) f $ 69,393 Accounts receivable, less allowance for doubtful accounts 91,508 13,382 a 104,890 Inventories 6,535 — 6,535 Prepaid expenses and other current assets 20,338 (1,251 ) a,f 19,087 Income tax receivable 4,713 (4,713 ) d — Total current assets 192,497 7,408 199,905 Property and equipment, net of accumulated depreciation 167,621 — 167,621 Deferred tax assets — 4,596 d 4,596 Intangible assets, net of accumulated amortization 24,966 — 24,966 Other long-term assets 19,639 — 19,639 Goodwill 570,946 393 c 571,339 Total assets $ 975,669 $ 12,397 $ 988,066 Liabilities and Equity Accounts payable $ 52,849 $ — $ 52,849 Accrued compensation and benefits 30,881 — 30,881 Accrued expenses and other current liabilities 48,961 13,989 d 62,950 Current portion of long-term debt 46,660 — 46,660 Total current liabilities 179,351 13,989 193,340 Long-term debt, less current portion 509,983 — 509,983 Income tax receivable agreement payable 6,037 — 6,037 Other long-term liabilities 33,819 (3 ) d 33,816 Deferred tax liabilities 4,696 (4,696 ) d — Total liabilities 733,886 9,290 743,176 Commitments and contingencies Noncontrolling interests subject to put provisions 145,500 (4,763 ) e 140,737 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,458,837 issued and outstanding 195 — 195 Additional paid-in capital 69,170 24,169 b,c 93,339 Receivable from noncontrolling interests (477 ) — (477 ) Accumulated deficit (142,493 ) (20,652 ) a,b,c,d,f (163,145 ) Accumulated other comprehensive income (loss), net of tax 1,227 (214 ) d 1,013 Total American Renal Associates Holdings, Inc. deficit (72,378 ) 3,303 (69,075 ) Noncontrolling interests not subject to put provisions 168,661 4,567 a,b,c,d,f 173,228 Total equity 96,283 7,870 104,153 Total liabilities and equity $ 975,669 $ 12,397 $ 988,066 As of September 30, 2018 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 61,872 $ (10 ) f $ 61,862 Accounts receivable, less allowance for doubtful accounts 90,596 8,082 a 98,678 Inventories 6,382 — 6,382 Prepaid expenses and other current assets 20,608 (1,892 ) a,f 18,716 Income tax receivable 5,306 (5,306 ) d — Total current assets 184,764 874 185,638 Property and equipment, net of accumulated depreciation 168,346 — 168,346 Deferred tax assets — 4,596 d 4,596 Intangible assets, net of accumulated amortization 24,811 — 24,811 Other long-term assets 18,198 — 18,198 Goodwill 570,944 395 c 571,339 Total assets $ 967,063 $ 5,865 $ 972,928 Liabilities and Equity Accounts payable $ 54,023 $ — $ 54,023 Accrued compensation and benefits 34,658 — 34,658 Accrued expenses and other current liabilities 43,153 13,385 d 56,538 Current portion of long-term debt 47,206 — 47,206 Total current liabilities 179,040 13,385 192,425 Long-term debt, less current portion 506,750 — 506,750 Income tax receivable agreement payable 9,476 — 9,476 Other long-term liabilities 24,378 (3 ) d 24,375 Deferred tax liabilities 4,843 (4,843 ) d — Total liabilities 724,487 8,539 733,026 Commitments and contingencies Noncontrolling interests subject to put provisions 150,152 (8,916 ) b 141,236 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 32,514,777 issued and outstanding 195 — 195 Additional paid-in capital 65,965 27,252 b,c 93,217 Receivable from noncontrolling interests (1,340 ) — (1,340 ) Accumulated deficit (140,003 ) (23,875 ) a,b,c,d,f (163,878 ) Accumulated other comprehensive income (loss), net of tax 1,654 (214 ) d 1,440 Total American Renal Associates Holdings, Inc. deficit (73,529 ) 3,163 (70,366 ) Noncontrolling interests not subject to put provisions 165,953 3,079 a,b,c,d,f 169,032 Total equity 92,424 6,242 98,666 Total liabilities and equity $ 967,063 $ 5,865 $ 972,928 Following are the Condensed Consolidated Balance Sheets for the interim quarters ended 2017 (tables in thousands, except per share data): As of March 31, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 84,003 $ (10 ) f $ 83,993 Accounts receivable, less allowance for doubtful accounts 77,495 48,354 a 125,849 Inventories 4,648 — 4,648 Prepaid expenses and other current assets 18,217 — 18,217 Income tax receivable 9,415 (9,415 ) d — Total current assets 193,778 38,929 232,707 Property and equipment, net of accumulated depreciation 167,338 — 167,338 Deferred tax assets — 9,691 d 9,691 Intangible assets, net of accumulated amortization 25,681 — 25,681 Other long-term assets 7,472 — 7,472 Goodwill 573,147 (55 ) c 573,092 Total assets $ 967,416 $ 48,565 $ 1,015,981 Liabilities and Equity Accounts payable $ 24,605 $ — $ 24,605 Accrued compensation and benefits 26,092 — 26,092 Accrued expenses and other current liabilities 45,075 13,484 d 58,559 Current portion of long-term debt 45,559 — 45,559 Total current liabilities 141,331 13,484 154,815 Long-term debt, less current portion 520,364 — 520,364 Income tax receivable agreement payable 16,683 — 16,683 Other long-term liabilities 12,826 (3 ) d 12,823 Deferred tax liabilities 1,522 (1,522 ) d — Total liabilities 692,726 11,959 704,685 Commitments and contingencies Noncontrolling interests subject to put provisions 132,465 25,621 b 158,086 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 31,143,998 issued and outstanding 184 — 184 Additional paid-in capital 93,596 364 b,c 93,960 Receivable from noncontrolling interests (747 ) — (747 ) Accumulated deficit (129,897 ) (3,526 ) a,b,c,d,f (133,423 ) Accumulated other comprehensive income (loss), net of tax (744 ) — (744 ) Total American Renal Associates Holdings, Inc. deficit (37,608 ) (3,162 ) (40,770 ) Noncontrolling interests not subject to put provisions 179,833 14,147 a,b,c,d,f 193,980 Total equity 142,225 10,985 153,210 Total liabilities and equity $ 967,416 $ 48,565 $ 1,015,981 As of June 30, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 74,933 $ (11 ) f $ 74,922 Accounts receivable, less allowance for doubtful accounts 77,841 39,819 a 117,660 Inventories 4,960 — 4,960 Prepaid expenses and other current assets 23,150 — 23,150 Income tax receivable 10,254 (10,254 ) d — Total current assets 191,138 29,554 220,692 Property and equipment, net of accumulated depreciation 165,495 — 165,495 Deferred tax assets — 9,635 d 9,635 Intangible assets, net of accumulated amortization 25,638 — 25,638 Other long-term assets 8,885 — 8,885 Goodwill 573,147 (347 ) c 572,800 Total assets $ 964,303 $ 38,842 $ 1,003,145 Liabilities and Equity Accounts payable $ 28,184 $ — $ 28,184 Accrued compensation and benefits 28,654 — 28,654 Accrued expenses and other current liabilities 60,663 10,032 d 70,695 Current portion of long-term debt 45,711 — 45,711 Total current liabilities 163,212 10,032 173,244 Long-term debt, less current portion 516,442 — 516,442 Income tax receivable agreement payable 15,600 — 15,600 Other long-term liabilities 13,859 (3 ) d 13,856 Deferred tax liabilities 1,128 (1,128 ) d — Total liabilities 710,241 8,901 719,142 Commitments and contingencies Noncontrolling interests subject to put provisions 113,925 18,569 b 132,494 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 31,283,812 issued and outstanding 185 — 185 Additional paid-in capital 95,369 6,006 b,c 101,375 Receivable from noncontrolling interests (415 ) — (415 ) Accumulated deficit (132,003 ) (6,585 ) a,b,c,d,f (138,588 ) Accumulated other comprehensive income (loss), net of tax (1,420 ) — (1,420 ) Total American Renal Associates Holdings, Inc. deficit (38,284 ) (579 ) (38,863 ) Noncontrolling interests not subject to put provisions 178,421 11,951 a,b,c,d,f 190,372 Total equity 140,137 11,372 151,509 Total liabilities and equity $ 964,303 $ 38,842 $ 1,003,145 As of September 30, 2017 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 67,593 $ (10 ) f $ 67,583 Accounts receivable, less allowance for doubtful accounts 81,234 40,026 a 121,260 Inventories 4,672 — 4,672 Prepaid expenses and other current assets 17,133 — 17,133 Income tax receivable 8,071 (8,071 ) d — Total current assets 178,703 31,945 210,648 Property and equipment, net of accumulated depreciation 166,890 — 166,890 Deferred tax assets — 9,635 d 9,635 Intangible assets, net of accumulated amortization 25,488 — 25,488 Other long-term assets 8,636 — 8,636 Goodwill 572,702 (282 ) c 572,420 Total assets $ 952,419 $ 41,298 $ 993,717 Liabilities and Equity Accounts payable $ 33,863 $ — $ 33,863 Accrued compensation and benefits 31,767 — 31,767 Accrued expenses and other current liabilities 43,797 13,402 d 57,199 Current portion of long-term debt 44,189 — 44,189 Total current liabilities 153,616 13,402 167,018 Long-term debt, less current portion 514,846 — 514,846 Income tax receivable agreement payable 11,900 — 11,900 Other long-term liabilities 15,713 — 15,713 Deferred tax liabilities 1,110 (1,110 ) d — Total liabilities 697,185 12,292 709,477 Commitments and contingencies Noncontrolling interests subject to put provisions 110,988 22,728 b 133,716 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 31,314,217 issued and outstanding 186 — 186 Additional paid-in capital 94,158 1,201 b,c 95,359 Receivable from noncontrolling interests (484 ) — (484 ) Accumulated deficit (124,020 ) (7,180 ) a,b,c,d,f (131,200 ) Accumulated other comprehensive income (loss), net of tax (1,447 ) — (1,447 ) Total American Renal Associates Holdings, Inc. deficit (31,607 ) (5,979 ) (37,586 ) Noncontrolling interests not subject to put provisions 175,853 12,257 a,b,c,d,f 188,110 Total equity 144,246 6,278 150,524 Total liabilities and equity $ 952,419 $ 41,298 $ 993,717 Following are the Condensed Consolidated Balance Sheets for the interim quarters ended 2016 (tables in thousands, except per share data): As of March 31, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 95,965 $ (4 ) f $ 95,961 Accounts receivable, less allowance for doubtful accounts 75,831 43,492 a 119,323 Inventories 5,515 — 5,515 Prepaid expenses and other current assets 19,507 (112 ) c 19,395 Income tax receivable 2,661 (2,661 ) d — Total current assets 199,479 40,715 240,194 Property and equipment, net of accumulated depreciation 151,204 — 151,204 Intangible assets, net of accumulated amortization 25,877 — 25,877 Other long-term assets 6,574 — 6,574 Goodwill 569,315 (54 ) c 569,261 Total assets $ 952,449 $ 40,661 $ 993,110 Liabilities and Equity Accounts payable $ 23,857 $ — $ 23,857 Accrued compensation and benefits 21,496 — 21,496 Accrued expenses and other current liabilities 31,110 14,100 d 45,210 Current portion of long-term debt 27,171 — 27,171 Total current liabilities 103,634 14,100 117,734 Long-term debt, less current portion 661,369 — 661,369 Other long-term liabilities 9,927 — 9,927 Deferred tax liabilities 15,096 (7,142 ) d 7,954 Total liabilities 790,026 6,958 796,984 Commitments and contingencies Noncontrolling interests subject to put provisions 107,414 17,558 b 124,972 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 29,770,000 issued and outstanding 98 — 98 Additional paid-in capital 457 6,396 b,c 6,853 Receivable from noncontrolling interests (605 ) — (605 ) Accumulated deficit (124,505 ) (3,435 ) a,b,c,d,f (127,940 ) Accumulated other comprehensive income (loss), net of tax (401 ) — (401 ) Total American Renal Associates Holdings, Inc. deficit (124,956 ) 2,961 (121,995 ) Noncontrolling interests not subject to put provisions 179,965 13,184 a,b,c,d,f 193,149 Total equity 55,009 16,145 71,154 Total liabilities and equity $ 952,449 $ 40,661 $ 993,110 As of June 30, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 93,268 $ (6 ) f $ 93,262 Accounts receivable, less allowance for doubtful accounts 76,904 54,081 a 130,985 Inventories 4,790 — 4,790 Prepaid expenses and other current assets 14,977 (75 ) c 14,902 Income tax receivable 144 (144 ) d — Total current assets 190,083 53,856 243,939 Property and equipment, net of accumulated depreciation 160,887 — 160,887 Intangible assets, net of accumulated amortization 25,938 — 25,938 Other long-term assets 6,174 — 6,174 Goodwill 569,930 (54 ) c 569,876 Total assets $ 953,012 $ 53,802 $ 1,006,814 Liabilities and Equity Accounts payable $ 23,515 $ — $ 23,515 Accrued compensation and benefits 25,469 — 25,469 Accrued expenses and other current liabilities 45,642 11,176 d 56,818 Current portion of long-term debt 40,579 — 40,579 Total current liabilities 135,205 11,176 146,381 Long-term debt, less current portion 517,798 — 517,798 Income tax receivable agreement payable 27,800 — 27,800 Other long-term liabilities 10,361 (6 ) d 10,355 Deferred tax liabilities 7,169 785 d 7,954 Total liabilities 698,333 11,955 710,288 Commitments and contingencies Noncontrolling interests subject to put provisions 134,762 16,862 b 151,624 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 30,845,109 issued and outstanding 184 — 184 Additional paid-in capital 72,405 9,444 b,c 81,849 Receivable from noncontrolling interests (498 ) — (498 ) Accumulated deficit (133,597 ) (1,402 ) a,b,c,d,f (134,999 ) Accumulated other comprehensive income (loss), net of tax (301 ) — (301 ) Total American Renal Associates Holdings, Inc. deficit (61,807 ) 8,042 (53,765 ) Noncontrolling interests not subject to put provisions 181,724 16,943 a,b,c,d,f 198,667 Total equity 119,917 24,985 144,902 Total liabilities and equity $ 953,012 $ 53,802 $ 1,006,814 As of September 30, 2016 As Reported Restatement Adjustments Reference As Restated Assets Cash $ 105,149 $ (11 ) f $ 105,138 Accounts receivable, less allowance for doubtful accounts 77,253 53,265 a 130,518 Inventories 4,468 — 4,468 Prepaid expenses and other current assets 12,951 (37 ) f 12,914 Income tax receivable 4,656 (4,656 ) d — Total current assets 204,477 48,561 253,038 Property and equipment, net of accumulated depreciation 165,132 — 165,132 Intangible assets, net of accumulated amortization 25,943 — 25,943 Other long-term assets 6,593 — 6,593 Goodwill 573,107 (55 ) c 573,052 Total assets $ 975,252 $ 48,506 $ 1,023,758 Liabilities and Equity Accounts payable $ 23,277 $ — $ 23,277 Accrued compensation and benefits 29,092 — 29,092 Accrued expenses and other current liabilities 54,031 5,357 d 59,388 Current portion of long-term debt 43,582 — 43,582 Total current liabilities 149,982 5,357 155,339 Long-term debt, less current portion 520,017 — 520,017 Income tax receivable agreement payable 15,670 — 15,670 Other long-term liabilities 11,262 — 11,262 Deferred tax liabilities 6,722 1,232 d 7,954 Total liabilities 703,653 6,589 710,242 Commitments and contingencies Noncontrolling interests subject to put provisions 140,336 11,580 b 151,916 Equity: Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued — — — Common stock, $0.01 par value; 300,000,000 shares authorized; 30,868,050 issued and outstanding 184 — 184 Additional paid-in capital 69,765 14,400 b,c 84,165 Receivable from noncontrolling interests (562 ) — (562 ) Accumulated deficit (121,527 ) (699 ) a,b,c,d,f (122,226 ) Accumulated other comprehensive income (loss), net of tax (201 ) — (201 ) Total American Renal Associates Holdings, Inc. deficit (52,341 ) 13,701 (38,640 ) Noncontrolling interests not subject to put provisions 183,604 16,636 a,b,c,d,f 200,240 Total equ

Basis of Presentation and Org_2

Basis of Presentation and Organization (Details)	12 Months Ended
	Dec. 31, 2018USD ($)dialysis_clinicpatientstate	Dec. 31, 2017USD ($)dialysis_clinicpatientstate	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets	$ 985,843,000	$ 990,151,000	$ 972,928,000	$ 988,066,000	$ 986,228,000	$ 993,717,000	$ 1,003,145,000	$ 1,015,981,000	$ 1,040,228,000	$ 1,023,758,000	$ 1,006,814,000	$ 993,110,000
Number of dialysis clinics owned and operated | dialysis_clinic	241	228
Number of patients | patient	16,543	15,637
Number of states | state	27	26
American Renal Holdings Intermediate Company, LLC
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Percentage ownership of subsidiary	100.00%
Assets	$ 0
Percentage ownership of parent	100.00%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details)	3 Months Ended							6 Months Ended			9 Months Ended			12 Months Ended
	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2018USD ($)clinicperformance_obligationreporting_unitsegment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jun. 30, 2019USD ($)	Jan. 01, 2019USD ($)	Dec. 31, 2015USD ($)
Segment Information
Number of reportable segments | segment														1
Medicare recovery claims, other than standard														$ 15,820,000	$ 10,744,000	$ 9,224,000
Medicare recovery claims														$ 10,622,000	10,744,000	9,224,000
Accounts Receivable
Number of remaining performance obligations | performance_obligation														1
Payment received under government’s bundled payment system														80.00%
Revenue related to adjustments arising from a change in the transaction price														$ 5,521,000
Maximum percent any other payor of total patient accounts receivable														10.00%
Identified Non‑Amortizable Intangible Assets and Goodwill
Number of reporting units | reporting_unit														1
Goodwill	$ 571,341,000	$ 572,420,000	$ 572,800,000	$ 573,092,000	$ 573,052,000	$ 569,876,000	$ 569,261,000	$ 571,339,000	$ 572,800,000	$ 569,876,000	$ 571,339,000	$ 572,420,000	$ 573,052,000	$ 571,339,000	573,145,000	573,092,000			$ 569,264,000
Impairment charge														0	0	0
Impairment of Long Lived Assets
Impairment charge														0	0	0
Gain on business interruption insurance														375,000	0	0
Professional fees	$ 856,000		717,000			2,215,000	24,000	$ 856,000	717,000	2,239,000	$ 856,000	717,000	2,239,000	856,000	717,000	2,239,000
Provision for uncollectible accounts															19,503,000	17,745,000
Provision for uncollectible accounts recorded as a deduction to arrive at net revenue prior to the Company's adoption of ASU 2014-09		$ 2,752,000	$ 431,000	$ 1,955,000	$ 2,964,000	$ 1,596,000	$ 1,283,000		$ 2,386,000	$ 2,879,000		$ 5,138,000	$ 5,843,000		8,316,000	5,441,000
Current assets held for sale														577,000	0	0
Accounts Receivable, Credit Loss Expense (Reversal)														$ 3,270,000	$ 8,676,000	$ 9,733,000
Minimum
Amortizable Intangible Assets
Amortizable period														5 years
Maximum
Amortizable Intangible Assets
Amortizable period														10 years
Buildings
Property and Equipment
Useful life														39 years
Equipment and information systems | Minimum
Property and Equipment
Useful life														3 years
Equipment and information systems | Maximum
Property and Equipment
Useful life														10 years
Included in prepaids and other assets
Segment Information
Medicare recovery claims														$ 10,622,000
Included in other current assets
Segment Information
Medicare recovery claims														$ 5,198,000
Subsequent Event
Impairment of Long Lived Assets
Current assets held for sale																	$ 14,061,000
Accounting Standards Update 2016-02 | Subsequent Event
Impairment of Long Lived Assets
Right-of-use asset																		$ 138,000,000
Lease liability																		$ 149,000,000
FLORIDA
Impairment of Long Lived Assets
Number of clinics | clinic														44
TEXAS
Impairment of Long Lived Assets
Number of clinics | clinic														26
Retained Earnings
Impairment of Long Lived Assets
Reclassification of stranded tax effects related to the Tax Cuts and Jobs Act of 2017														$ 214,000
Customer Concentration Risk | Medicare And Medicaid Programs | Accounts Receivable
Accounts Receivable
Patient accounts receivable from Medicare and Medicaid programs														70.40%	56.20%	42.30%
Certain Clinics In Maryland | Disposal Group, Held-for-sale, Not Discontinued Operations
Impairment of Long Lived Assets
Impairment charge														$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies Schedule of Revenue (Details) - Revenue	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Concentration Risk [Line Items]
Composition of patient care service revenue	100.00%	100.00%	100.00%
Medicare and Medicare Advantage
Concentration Risk [Line Items]
Composition of patient care service revenue	67.00%	61.00%	54.00%
Commercial and other
Concentration Risk [Line Items]
Composition of patient care service revenue	28.00%	35.00%	43.00%
Medicaid and Managed Medicaid
Concentration Risk [Line Items]
Composition of patient care service revenue	4.00%	3.00%	2.00%
Other
Concentration Risk [Line Items]
Composition of patient care service revenue	1.00%	1.00%	1.00%

Restatement of Consolidated F_3

Restatement of Consolidated Financial Statements - Restated Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Assets
Cash	$ 55,200	$ 61,862	$ 69,393	$ 64,273	$ 71,511	$ 67,583	$ 74,922	$ 83,993	$ 100,905	$ 105,138	$ 93,262	$ 95,961
Accounts receivable, net of allowance for doubtful accounts	99,526	98,678	104,890	110,331	112,642	121,260	117,660	125,849	130,211	130,518	130,985	119,323
Inventories	11,433	6,382	6,535	6,129	4,665	4,672	4,960	4,648	4,676	4,468	4,790	5,515
Prepaid expenses and other current assets	28,127	18,716	19,087	25,277	24,998	17,133	23,150	18,217	18,498	12,914	14,902	19,395
Income tax receivable		0	0	0	0	0	0	0	0	0	0	0
Total current assets	194,863	185,638	199,905	206,010	213,816	210,648	220,692	232,707	254,290	253,038	243,939	240,194
Property and equipment, net of accumulated depreciation	180,268	168,346	167,621	168,682	168,537	166,890	165,495	167,338	170,118	165,132	160,887	151,204
Deferred tax assets	0	4,596	4,596		0	9,635	9,635	9,691	10,349
Intangible assets, net of accumulated amortization	24,628	24,811	24,966	25,182	25,368	25,488	25,638	25,681	25,626	25,943	25,938	25,877
Other long-term assets	14,745	18,198	19,639	15,013	9,285	8,636	8,885	7,472	6,753	6,593	6,174	6,574
Goodwill	571,339	571,339	571,339	571,341	573,145	572,420	572,800	573,092	573,092	573,052	569,876	569,261	$ 569,264
Total assets	985,843	972,928	988,066	986,228	990,151	993,717	1,003,145	1,015,981	1,040,228	1,023,758	1,006,814	993,110
Liabilities and Equity
Accounts payable	59,082	54,023	52,849	40,885	33,421	33,863	28,184	24,605	31,127	23,277	23,515	23,857
Accrued compensation and benefits	34,587	34,658	30,881	27,160	28,985	31,767	28,654	26,092	29,103	29,092	25,469	21,496
Accrued expenses and other current liabilities	61,116	56,538	62,950	63,790	64,575	57,199	70,695	58,559	63,022	59,388	56,818	45,210
Current portion of long-term debt	42,855	47,206	46,660	45,121	44,534	44,189	45,711	45,559	48,274	43,582	40,579	27,171
Total current liabilities	197,640	192,425	193,340	176,956	171,515	167,018	173,244	154,815	171,526	155,339	146,381	117,734
Long-term debt, less current portion	517,511	506,750	509,983	512,822	515,554	514,846	516,442	520,364	522,058	520,017	517,798	661,369
Income tax receivable agreement payable	3,700	9,476	6,037	8,646	7,500	11,900	15,600	16,683	21,200	15,670	27,800
Other long-term liabilities	24,813	24,375	33,816	14,147	14,880	15,713	13,856	12,823	11,670	11,262	10,355	9,927
Deferred tax liabilities	3,169	0	0	422	422	0	0	0	0	7,954	7,954	7,954
Total liabilities	746,833	733,026	743,176	712,993	709,871	709,477	719,142	704,685	726,454	710,242	710,288	796,984
Commitments and contingencies
Noncontrolling interests subject to put provisions	129,099	141,236	140,737	139,791	130,438	133,716	132,494	158,086	150,049	151,916	151,624	124,972
Equity:
Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued	0	0	0	0	0	0	0	0	0	0	0	0
Common stock	196	195	195	195	193	186	185	184	184	184	184	98
Additional paid-in capital	105,715	93,217	93,339	98,243	99,098	95,359	101,375	93,960	100,687	84,165	81,849	6,853
Receivable from noncontrolling interests	(506)	(1,340)	(477)	(515)	(358)	(484)	(415)	(747)	(544)	(562)	(498)	(605)
Accumulated deficit	(164,451)	(163,878)	(163,145)	(139,486)	(135,898)	(131,200)	(138,588)	(133,423)	(131,301)	(122,226)	(134,999)	(127,940)
Accumulated other comprehensive income (loss), net of tax	76	1,440	1,013	546	(891)	(1,447)	(1,420)	(744)	(100)	(201)	(301)	(401)
Total American Renal Associates Holdings, Inc. deficit	(58,970)	(70,366)	(69,075)	(41,017)	(37,856)	(37,586)	(38,863)	(40,770)	(31,074)	(38,640)	(53,765)	(121,995)	$ (123,211)
Noncontrolling interests not subject to put provisions	168,881	169,032	173,228	174,461	187,698	188,110	190,372	193,980	194,799	200,240	198,667	193,149
Total equity	109,911	98,666	104,153	133,444	149,842	150,524	151,509	153,210	163,725	161,600	144,902	71,154
Total liabilities and equity	$ 985,843	972,928	988,066	986,228	990,151	993,717	1,003,145	1,015,981	1,040,228	1,023,758	1,006,814	993,110
As Reported
Assets
Cash		61,872	69,403	64,283	71,521	67,593	74,933	84,003	100,916	105,149	93,268	95,965
Accounts receivable, net of allowance for doubtful accounts		90,596	91,508	85,723	79,662	81,234	77,841	77,495	81,127	77,253	76,904	75,831
Inventories		6,382	6,535	7,642	4,665	4,672	4,960	4,648	4,676	4,468	4,790	5,515
Prepaid expenses and other current assets		20,608	20,338	24,478	24,998	17,133	23,150	18,217	18,498	12,951	14,977	19,507
Income tax receivable		5,306	4,713	7,835	6,745	8,071	10,254	9,415	5,163	4,656	144	2,661
Total current assets		184,764	192,497	189,961	187,591	178,703	191,138	193,778	210,380	204,477	190,083	199,479
Property and equipment, net of accumulated depreciation		168,346	167,621	168,682	168,537	166,890	165,495	167,338	170,118	165,132	160,887	151,204
Deferred tax assets		0	0			0	0	0	0
Intangible assets, net of accumulated amortization		24,811	24,966	25,182	25,368	25,488	25,638	25,681	25,626	25,943	25,938	25,877
Other long-term assets		18,198	19,639	15,013	9,285	8,636	8,885	7,472	6,753	6,593	6,174	6,574
Goodwill		570,944	570,946	570,946	573,427	572,702	573,147	573,147	573,147	573,107	569,930	569,315
Total assets		967,063	975,669	969,784	964,208	952,419	964,303	967,416	986,024	975,252	953,012	952,449
Liabilities and Equity
Accounts payable		54,023	52,849	40,885	33,421	33,863	28,184	24,605	31,127	23,277	23,515	23,857
Accrued compensation and benefits		34,658	30,881	27,160	28,985	31,767	28,654	26,092	29,103	29,092	25,469	21,496
Accrued expenses and other current liabilities		43,153	48,961	51,954	49,963	43,797	60,663	45,075	45,286	54,031	45,642	31,110
Current portion of long-term debt		47,206	46,660	45,121	44,534	44,189	45,711	45,559	48,274	43,582	40,579	27,171
Total current liabilities		179,040	179,351	165,120	156,903	153,616	163,212	141,331	153,790	149,982	135,205	103,634
Long-term debt, less current portion		506,750	509,983	512,822	515,554	514,846	516,442	520,364	522,058	520,017	517,798	661,369
Income tax receivable agreement payable		9,476	6,037	8,646	7,500	11,900	15,600	16,683	21,200	15,670	27,800
Other long-term liabilities		24,378	33,819	14,171	14,880	15,713	13,859	12,826	11,670	11,262	10,361	9,927
Deferred tax liabilities		4,843	4,696	9,560	8,991	1,110	1,128	1,522	1,278	6,722	7,169	15,096
Total liabilities		724,487	733,886	710,319	703,828	697,185	710,241	692,726	709,996	703,653	698,333	790,026
Commitments and contingencies
Noncontrolling interests subject to put provisions		150,152	145,500	148,769	139,895	110,988	113,925	132,465	130,365	140,336	134,762	107,414
Equity:
Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued		0	0	0	0	0	0	0	0	0	0	0
Common stock		195	195	195	193	186	185	184	184	184	184	98
Additional paid-in capital		65,965	69,170	68,632	67,853	94,158	95,369	93,596	95,062	69,765	72,405	457
Receivable from noncontrolling interests		(1,340)	(477)	(515)	(358)	(484)	(415)	(747)	(544)	(562)	(498)	(605)
Accumulated deficit		(140,003)	(142,493)	(124,485)	(123,789)	(124,020)	(132,003)	(129,897)	(128,646)	(121,527)	(133,597)	(124,505)
Accumulated other comprehensive income (loss), net of tax		1,654	1,227	760	(677)	(1,447)	(1,420)	(744)	(100)	(201)	(301)	(401)
Total American Renal Associates Holdings, Inc. deficit		(73,529)	(72,378)	(55,413)	(56,778)	(31,607)	(38,284)	(37,608)	(34,044)	(52,341)	(61,807)	(124,956)
Noncontrolling interests not subject to put provisions		165,953	168,661	166,109	177,263	175,853	178,421	179,833	179,707	183,604	181,724	179,965
Total equity		92,424	96,283	110,696	120,485	144,246	140,137	142,225	145,663	131,263	119,917	55,009
Total liabilities and equity		967,063	975,669	969,784	964,208	952,419	964,303	967,416	986,024	975,252	953,012	952,449
Restatement Adjustments
Assets
Cash		(10)	(10)	(10)	(10)	(10)	(11)	(10)	(11)	(11)	(6)	(4)
Accounts receivable, net of allowance for doubtful accounts		8,082	13,382	24,608	32,980	40,026	39,819	48,354	49,084	53,265	54,081	43,492
Inventories		0	0	(1,513)	0	0	0	0	0	0	0	0
Prepaid expenses and other current assets		(1,892)	(1,251)	799	0	0	0	0	0	(37)	(75)	(112)
Income tax receivable		(5,306)	(4,713)	(7,835)	(6,745)	(8,071)	(10,254)	(9,415)	(5,163)	(4,656)	(144)	(2,661)
Total current assets		874	7,408	16,049	26,225	31,945	29,554	38,929	43,910	48,561	53,856	40,715
Property and equipment, net of accumulated depreciation		0	0	0	0	0	0	0	0	0	0	0
Deferred tax assets		4,596	4,596			9,635	9,635	9,691	10,349
Intangible assets, net of accumulated amortization		0	0	0	0	0	0	0	0	0	0	0
Other long-term assets		0	0	0	0	0	0	0	0	0	0	0
Goodwill		395	393	395	(282)	(282)	(347)	(55)	(55)	(55)	(54)	(54)
Total assets		5,865	12,397	16,444	25,943	41,298	38,842	48,565	54,204	48,506	53,802	40,661
Liabilities and Equity
Accounts payable		0	0	0	0	0	0	0	0	0	0	0
Accrued compensation and benefits		0	0	0	0	0	0	0	0	0	0	0
Accrued expenses and other current liabilities		13,385	13,989	11,836	14,612	13,402	10,032	13,484	17,736	5,357	11,176	14,100
Current portion of long-term debt		0	0	0	0	0	0	0	0	0	0	0
Total current liabilities		13,385	13,989	11,836	14,612	13,402	10,032	13,484	17,736	5,357	11,176	14,100
Long-term debt, less current portion		0	0	0	0	0	0	0	0	0	0	0
Income tax receivable agreement payable		0	0	0	0	0	0	0	0	0	0
Other long-term liabilities		(3)	(3)	(24)	0	0	(3)	(3)	0	0	(6)	0
Deferred tax liabilities		(4,843)	(4,696)	(9,138)	(8,569)	(1,110)	(1,128)	(1,522)	(1,278)	1,232	785	(7,142)
Total liabilities		8,539	9,290	2,674	6,043	12,292	8,901	11,959	16,458	6,589	11,955	6,958
Commitments and contingencies
Noncontrolling interests subject to put provisions		(8,916)	(4,763)	(8,978)	(9,457)	22,728	18,569	25,621	19,684	11,580	16,862	17,558
Equity:
Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued		0	0	0	0	0	0	0	0	0	0	0
Common stock		0	0	0	0	0	0	0	0	0	0	0
Additional paid-in capital		27,252	24,169	29,611	31,245	1,201	6,006	364	5,625	14,400	9,444	6,396
Receivable from noncontrolling interests		0	0	0	0	0	0	0	0	0	0	0
Accumulated deficit		(23,875)	(20,652)	(15,001)	(12,109)	(7,180)	(6,585)	(3,526)	(2,655)	(699)	(1,402)	(3,435)
Accumulated other comprehensive income (loss), net of tax		(214)	(214)	(214)	(214)	0	0	0	0	0	0	0
Total American Renal Associates Holdings, Inc. deficit		3,163	3,303	14,396	18,922	(5,979)	(579)	(3,162)	2,970	13,701	8,042	2,961
Noncontrolling interests not subject to put provisions		3,079	4,567	8,352	10,435	12,257	11,951	14,147	15,092	16,636	16,943	13,184
Total equity		6,242	7,870	22,748	29,357	6,278	11,372	10,985	18,062	30,337	24,985	16,145
Total liabilities and equity		$ 5,865	$ 12,397	$ 16,444	$ 25,943	$ 41,298	$ 38,842	$ 48,565	$ 54,204	$ 48,506	$ 53,802	$ 40,661

Restatement of Consolidated F_4

Restatement of Consolidated Financial Statements - Restated Consolidated Balance Sheet (Parenthetical) (Details) - $ / shares	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Apr. 07, 2016	Mar. 31, 2016
Accounting Changes and Error Corrections [Abstract]
Preferred stock, par value (in USD per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01		$ 0.01
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000		1,000,000
Preferred stock, issued (in shares)	0	0	0	0	0	0	0	0	0	0	0		0
Common stock, par value (in USD per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000
Common stock, shares issued (in shares)	32,603,846	32,514,777	32,458,837	32,437,507	32,034,439	31,314,217	31,283,812	31,142,998	30,894,962	30,868,050	30,845,109		29,770,000
Common stock, shares outstanding (in shares)	32,603,846	32,514,777	32,458,837	32,437,507	32,034,439	31,314,217	31,283,812	31,142,998	30,894,962	30,868,050	30,845,109		29,770,000

Restatement of Consolidated F_5

Restatement of Consolidated Financial Statements - Restated Consolidated Statements of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended											6 Months Ended			9 Months Ended			12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Patient service operating revenues					$ 190,509	$ 190,670	$ 177,890	$ 178,249	$ 195,103	$ 197,752	$ 184,834		$ 356,139	$ 382,586		$ 546,809	$ 577,689		$ 737,318	$ 772,221
Provision for uncollectible accounts						(2,752)	(431)	(1,955)	(2,964)	(1,596)	(1,283)		(2,386)	(2,879)		(5,138)	(5,843)		(8,316)	(5,441)
Net patient service operating revenues					187,331	187,918	177,459	176,294	192,139	196,156	183,551		353,753	379,707		541,671	571,846		729,002	766,780
Operating expenses:
Patient care costs		$ 145,939	$ 141,468	$ 134,077		119,739	118,568	120,301	116,115	109,779	105,455	$ 275,545	238,869	215,234	$ 421,484	358,608	331,349	$ 570,009	483,101	452,453
General and administrative		24,619	26,434	25,067		22,036	26,218	31,309	33,354	32,039	21,643	51,501	57,527	53,682	76,120	79,563	87,036	101,101	102,093	127,921
Transaction-related costs				856			717			2,215	24	856	717	2,239	856	717	2,239	856	717	2,239
Depreciation and amortization		10,023	9,814	9,623		9,438	9,382	9,074	8,687	8,252	7,677	19,437	18,456	15,929	29,460	27,894	24,616	39,802	37,634	33,862
Certain legal and other matters		1,028	32,546	4,103		3,481	4,297	3,936	4,042			36,649	8,233		37,677	11,714	4,042		15,249	6,779
Total operating expenses		181,609	210,262	173,726		154,694	159,182	164,620	162,198	152,285	134,799	383,988	323,802	287,084	565,597	478,496	449,282	750,454	638,794	623,254
Operating income	$ 22,949	24,110	(4,310)	12,573	27,033	33,224	18,277	11,674	29,941	43,871	48,752	8,263	29,951	92,623	32,373	63,175	122,564	55,322	90,208	143,526
Interest expense, net		(8,242)	(8,136)	(7,457)		(7,255)	(7,188)	(7,609)	(7,372)	(8,951)	(12,263)	(15,593)	(14,797)	(21,214)	(23,835)	(22,052)	(28,586)	(32,632)	(29,309)	(35,959)
Loss on early extinguishment of debt							(526)			(4,708)			(526)	(4,708)		(526)	(4,708)	0	(526)	(4,708)
Change in fair value of income tax receivable agreement		(3,480)	1,736	(1,021)		3,585	(2,641)	4,517	12,565	(7,835)		715	1,876	(7,835)	(2,765)	5,461	4,730	2,673	7,234	1,286
Income before income taxes		12,388	(10,710)	4,095		29,554	7,922	8,582	35,134	22,377	36,489	(6,615)	16,504	58,866	5,773	46,058	94,000	25,363	67,607	104,145
Income tax (benefit) expense		(124)	(2,327)	(3,069)		3,763	(1,837)	(3,180)	(983)	1,208	4,499	(5,396)	(5,017)	5,707	(5,520)	(1,254)	4,724	2,896	9,471	2,479
Net income (loss)		12,512	(8,383)	7,164		25,791	9,759	11,762	36,117	21,169	31,990	(1,219)	21,521	53,159	11,293	47,312	89,276	22,467	58,136	101,666
Less: Net income attributable to noncontrolling interests		(13,246)	(15,276)	(10,966)		(18,295)	(14,832)	(13,884)	(23,345)	(28,242)	(25,469)	(26,242)	(28,716)	(53,711)	(39,488)	(47,011)	(77,056)	(51,234)	(62,733)	(98,520)
Net (loss) income attributable to American Renal Associates Holdings, Inc.	$ (572)	(734)	(23,659)	(3,802)	$ (4,898)	7,496	(5,073)	(2,122)	12,772	(7,073)	6,521	(27,461)	(7,195)	(552)	(28,195)	301	12,220	(28,767)	(4,597)	3,146
Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests		(580)	(1,248)	497		559	(2,884)	(10,407)	(3,339)	(10,322)	0	(751)	(13,291)	(10,322)	(1,331)	(12,732)	(13,661)	(2,566)	(11,503)	(10,067)
Net income (loss) attributable to common shareholders		$ (1,314)	$ (24,907)	$ (3,305)		$ 8,055	$ (7,957)	$ (12,529)	$ 9,433	$ (17,395)	$ 6,521	$ (28,212)	$ (20,486)	$ (10,874)	$ (29,526)	$ (12,431)	$ (1,441)	$ (31,333)	$ (16,100)	$ (6,921)
Loss per share:
Basic (in USD per share)	$ (0.06)	$ (0.04)	$ (0.78)	$ (0.10)	$ (0.12)	$ 0.26	$ (0.26)	$ (0.41)	$ 0.31	$ (0.61)	$ 0.29	$ (0.89)	$ (0.66)	$ (0.43)	$ (0.93)	$ (0.40)	$ (0.05)	$ (0.98)	$ (0.52)	$ (0.25)
Diluted (in USD per share)	$ (0.06)	$ (0.04)	$ (0.78)	$ (0.10)	$ (0.12)	$ 0.24	$ (0.26)	$ (0.41)	$ 0.30	$ (0.61)	$ 0.29	$ (0.89)	$ (0.66)	$ (0.43)	$ (0.93)	$ (0.40)	$ (0.05)	$ (0.98)	$ (0.52)	$ (0.25)
Weighted-average number of common shares outstanding
Basic (in shares)		32,005,544	31,932,705	31,800,553		31,095,418	30,986,689	30,907,482	30,865,350	28,406,999	22,213,967	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297	31,965,844	31,081,824	28,118,673
Diluted (in shares)		32,005,544	31,932,705	31,800,553		33,833,822	30,986,689	30,907,482	31,436,814	28,406,999	22,785,670	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297	31,965,844	31,081,824	28,118,673
Cash dividends declared per share (in USD per share)										$ 1.30				$ 1.3			$ 1.30	$ 0	$ 0	$ 1.30
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Patient service operating revenues						$ 189,497	$ 187,602	$ 178,632	$ 194,857	$ 186,938	$ 173,554		$ 366,234	$ 360,492		$ 555,731	$ 555,349		$ 752,510	$ 756,329
Provision for uncollectible accounts						(1,786)	(1,610)	(1,607)	(1,902)	(1,371)	(1,423)		(3,217)	(2,794)		(5,003)	(4,696)		(7,404)	(6,562)
Net patient service operating revenues						187,711	185,992	177,025	192,955	185,567	172,131		363,017	357,698		550,728	550,653		745,106	749,767
Operating expenses:
Patient care costs		$ 145,300	$ 140,562	$ 133,731		119,599	118,059	120,301	116,115	109,779	105,455	$ 274,293	238,360	215,234	$ 419,593	357,959	331,349		482,450	452,449
General and administrative		24,619	26,803	24,960		22,292	26,381	31,244	33,359	31,942	21,499	51,763	57,625	53,441	76,382	79,917	86,800		102,598	127,631
Transaction-related costs				856			717			2,215	24	856	717	2,239	856	717	2,239		717	2,239
Depreciation and amortization		10,023	9,814	9,623		9,438	9,382	9,074	8,687	8,252	7,677	19,437	18,456	15,929	29,460	27,894	24,616		37,634	33,862
Certain legal and other matters		1,028	32,546	4,103		3,481	4,297	3,936	4,042			36,649	8,233		37,677	11,714	4,042		15,249	6,779
Total operating expenses		180,970	209,725	173,273		154,810	158,836	164,555	162,203	152,188	134,655	382,998	323,391	286,843	563,968	478,201	449,046		638,648	622,960
Operating income		30,049	7,453	21,399		32,901	27,156	12,470	30,752	33,379	37,476	28,852	39,626	70,855	58,901	72,527	101,607		106,458	126,807
Interest expense, net		(8,241)	(8,131)	(7,457)		(7,255)	(7,188)	(7,609)	(7,372)	(8,941)	(12,258)	(15,588)	(14,797)	(21,199)	(23,829)	(22,052)	(28,571)		(29,289)	(35,933)
Loss on early extinguishment of debt							(526)			(4,708)			(526)	(4,708)		(526)	(4,708)		(526)	(4,708)
Change in fair value of income tax receivable agreement		(3,480)	1,736	(1,021)		3,585	(2,641)	4,517	12,565	(7,835)		715	1,876	(7,835)	(2,765)	5,461	4,730		7,234	1,286
Income before income taxes		18,328	1,058	12,921		29,231	16,801	9,378	35,945	11,895	25,218	13,979	26,179	37,113	32,307	55,410	73,058		83,877	87,452
Income tax (benefit) expense		34	(1,219)	(792)		2,559	410	(3,524)	(101)	(1,147)	2,661	(2,011)	(3,114)	1,514	(1,977)	(555)	1,413		8,194	(753)
Net income (loss)		18,294	2,277	13,713		26,672	16,391	12,902	36,046	13,042	22,557	15,990	29,293	35,599	34,284	55,965	71,645		75,683	88,205
Less: Net income attributable to noncontrolling interests		(15,804)	(20,285)	(14,623)		(18,689)	(18,497)	(14,153)	(23,622)	(22,488)	(18,801)	(34,908)	(32,650)	(41,289)	(50,712)	(51,339)	(64,911)		(70,826)	(88,590)
Net (loss) income attributable to American Renal Associates Holdings, Inc.		2,490	(18,008)	(910)		7,983	(2,106)	(1,251)	12,424	(9,446)	3,756	(18,918)	(3,357)	(5,690)	(16,428)	4,626	6,734		4,857	(385)
Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests		(481)	(884)	582		5	(2,527)	(11,083)	(1,752)	(12,133)	0	(302)	(13,610)	(12,133)	(783)	(13,605)	(13,885)		(12,276)	(7,404)
Net income (loss) attributable to common shareholders		$ 2,009	$ (18,892)	$ (328)		$ 7,988	$ (4,633)	$ (12,334)	$ 10,672	$ (21,579)	$ 3,756	$ (19,220)	$ (16,967)	$ (17,823)	$ (17,211)	$ (8,979)	$ (7,151)		$ (7,419)	$ (7,789)
Loss per share:
Basic (in USD per share)		$ 0.06	$ (0.59)	$ (0.01)		$ 0.26	$ (0.15)	$ (0.40)	$ 0.35	$ (0.76)	$ 0.17	$ (0.60)	$ (0.55)	$ (0.70)	$ (0.54)	$ (0.29)	$ (0.26)		$ (0.24)	$ (0.28)
Diluted (in USD per share)		$ 0.06	$ (0.59)	$ (0.01)		$ 0.24	$ (0.15)	$ (0.40)	$ 0.34	$ (0.76)	$ 0.16	$ (0.60)	$ (0.55)	$ (0.70)	$ (0.54)	$ (0.29)	$ (0.26)		$ (0.24)	$ (0.28)
Weighted-average number of common shares outstanding
Basic (in shares)		32,005,544	31,932,705	31,800,553		31,095,418	30,986,689	30,907,482	30,865,350	28,406,999	22,213,967	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297		31,081,824	28,116,673
Diluted (in shares)		34,578,592	31,932,705	31,800,553		33,833,822	30,986,689	30,907,482	31,436,814	28,406,999	22,785,670	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297		31,081,824	28,116,673
Cash dividends declared per share (in USD per share)										$ 1.30				$ 1.3			$ 1.30			$ 1.30
Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Patient service operating revenues						$ 1,173	$ (9,712)	$ (383)	$ 246	$ 10,814	$ 11,280		$ (10,095)	$ 22,094		$ (8,922)	$ 22,340		$ (15,192)	$ 15,892
Provision for uncollectible accounts						(966)	1,179	(348)	(1,062)	(225)	140		831	(85)		(135)	(1,147)		(912)	1,121
Net patient service operating revenues						207	(8,533)	(731)	(816)	10,589	11,420		(9,264)	22,009		(9,057)	21,193		(16,104)	17,013
Operating expenses:
Patient care costs		$ 639	$ 906	$ 346		140	509	0	0	0	0	$ 1,252	509	0	$ 1,891	649	0		651	4
General and administrative		0	(369)	107		(256)	(163)	65	(5)	97	144	(262)	(98)	241	(262)	(354)	236		(505)	290
Transaction-related costs				0			0			0	0	0	0	0	0	0	0		0	0
Depreciation and amortization		0	0	0		0	0	0	0	0	0	0	0	0	0	0	0		0	0
Certain legal and other matters		0	0	0		0	0	0	0			0	0		0	0	0		0	0
Total operating expenses		639	537	453		(116)	346	65	(5)	97	144	990	411	241	1,629	295	236		146	294
Operating income		(5,939)	(11,763)	(8,826)		323	(8,879)	(796)	(811)	10,492	11,276	(20,589)	(9,675)	21,768	(26,528)	(9,352)	20,957		(16,250)	16,719
Interest expense, net		(1)	(5)	0		0	0	0	0	(10)	(5)	(5)	0	(15)	(6)	0	(15)		(20)	(26)
Loss on early extinguishment of debt							0			0			0	0		0	0		0	0
Change in fair value of income tax receivable agreement		0	0	0		0	0	0	0	0		0	0	0	0	0	0		0	0
Income before income taxes		(5,940)	(11,768)	(8,826)		323	(8,879)	(796)	(811)	10,482	11,271	(20,594)	(9,675)	21,753	(26,534)	(9,352)	20,942		(16,270)	16,693
Income tax (benefit) expense		(158)	(1,108)	(2,277)		1,204	(2,247)	344	(882)	2,355	1,838	(3,385)	(1,903)	4,193	(3,543)	(699)	3,311		1,277	3,232
Net income (loss)		(5,782)	(10,660)	(6,549)		(881)	(6,632)	(1,140)	71	8,127	9,433	(17,209)	(7,772)	17,560	(22,991)	(8,653)	17,631		(17,547)	13,461
Less: Net income attributable to noncontrolling interests		2,558	5,009	3,657		394	3,665	269	277	(5,754)	(6,668)	8,666	3,934	(12,422)	11,224	4,328	(12,145)		8,093	(9,930)
Net (loss) income attributable to American Renal Associates Holdings, Inc.		(3,224)	(5,651)	(2,892)		(487)	(2,967)	(871)	348	2,373	2,765	(8,543)	(3,838)	5,138	(11,767)	(4,325)	5,486		(9,454)	3,531
Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests		(99)	(364)	(85)		554	(357)	676	(1,587)	1,811	0	(449)	319	1,811	(548)	873	224		773	(2,663)
Net income (loss) attributable to common shareholders		$ (3,323)	$ (6,015)	$ (2,977)		$ 67	$ (3,324)	$ (195)	$ (1,239)	$ 4,184	$ 2,765	$ (8,992)	$ (3,519)	$ 6,949	$ (12,315)	$ (3,452)	$ 5,710		$ (8,681)	$ 868

Restatement of Consolidated F_6

Restatement of Consolidated Financial Statements - Restated Consolidated Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended									6 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	$ 12,512	$ (8,383)	$ 7,164	$ 25,791	$ 9,759	$ 11,762	$ 36,117	$ 21,169	$ 31,990	$ (1,219)	$ 21,521	$ 53,159	$ 11,293	$ 47,312	$ 89,276	$ 22,467	$ 58,136	$ 101,666
Unrealized gain (loss) on derivative agreements, net of tax	427	467	1,651	(27)	(676)	(644)	100	100	100	2,118	(1,320)	200	2,545	(1,347)	300	1,181	(791)	401
Total comprehensive income	12,939	(7,916)	8,815	25,764	9,083	11,118	36,217	21,269	32,090	899	20,201	53,359	13,838	45,965	89,576	23,648	57,345	102,067
Less: Comprehensive income attributable to noncontrolling interests	(13,246)	(15,276)	(10,966)	(18,295)	(14,832)	(13,884)	(23,345)	(28,242)	(25,469)	(26,242)	(28,716)	(53,711)	(39,488)	(47,011)	(77,056)	(51,234)	(62,733)	(98,520)
Total comprehensive (loss) income attributable to American Renal Associates Holdings, Inc.	(307)	(23,192)	(2,151)	7,469	(5,749)	(2,766)	12,872	(6,973)	6,621	(25,343)	(8,515)	(352)	(25,650)	(1,046)	12,520	$ (27,586)	(5,388)	3,547
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	18,294	2,277	13,713	26,672	16,391	12,902	36,046	13,042	22,557	15,990	29,293	35,599	34,284	55,965	71,645		75,683	88,205
Unrealized gain (loss) on derivative agreements, net of tax	427	467	1,651	(27)	(676)	(644)	100	100	100	2,118	(1,320)	200	2,545	(1,347)	300		(577)	401
Total comprehensive income	18,721	2,744	15,364	26,645	15,715	12,258	36,146	13,142	22,657	18,108	27,973	35,799	36,829	54,618	71,945		75,106	88,606
Less: Comprehensive income attributable to noncontrolling interests	(15,804)	(20,285)	(14,623)	(18,689)	(18,497)	(14,153)	(23,622)	(22,488)	(18,801)	(34,908)	(32,650)	(41,289)	(50,712)	(51,339)	(64,911)		(70,826)	(88,590)
Total comprehensive (loss) income attributable to American Renal Associates Holdings, Inc.	2,917	(17,541)	741	7,956	(2,782)	(1,895)	12,524	(9,346)	3,856	(16,800)	(4,677)	(5,490)	(13,883)	3,279	7,034		4,280	16
Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	(5,782)	(10,660)	(6,549)	(881)	(6,632)	(1,140)	71	8,127	9,433	(17,209)	(7,772)	17,560	(22,991)	(8,653)	17,631		(17,547)	13,461
Unrealized gain (loss) on derivative agreements, net of tax	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0		(214)	0
Total comprehensive income	(5,782)	(10,660)	(6,549)	(881)	(6,632)	(1,140)	71	8,127	9,433	(17,209)	(7,772)	17,560	(22,991)	(8,653)	17,631		(17,761)	13,461
Less: Comprehensive income attributable to noncontrolling interests	2,558	5,009	3,657	394	3,665	269	277	(5,754)	(6,668)	8,666	3,934	(12,422)	11,224	4,328	(12,145)		8,093	(9,930)
Total comprehensive (loss) income attributable to American Renal Associates Holdings, Inc.	$ (3,224)	$ (5,651)	$ (2,892)	$ (487)	$ (2,967)	$ (871)	$ 348	$ 2,373	$ 2,765	$ (8,543)	$ (3,838)	$ 5,138	$ (11,767)	$ (4,325)	$ 5,486		$ (9,668)	$ 3,531

Restatement of Consolidated F_7

Restatement of Consolidated Financial Statements - Restated Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended									6 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income	$ 12,512	$ (8,383)	$ 7,164	$ 25,791	$ 9,759	$ 11,762	$ 36,117	$ 21,169	$ 31,990	$ (1,219)	$ 21,521	$ 53,159	$ 11,293	$ 47,312	$ 89,276	$ 22,467	$ 58,136	$ 101,666
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization			9,623			9,074			7,677	19,437	18,456	15,929	29,460	27,894	24,616	39,802	37,634	33,862
Amortization of discounts, fees and deferred financing costs			497			530			797	989	1,065	1,807	1,384	1,534	2,432	1,981	2,031	2,595
Loss on early extinguishment of debt					526			4,708			526	4,708		526	4,708	0	526	4,708
Stock-based compensation			1,264			10,088			386	2,927	13,731	10,565	4,174	14,762	23,238	5,721	15,872	40,285
Premium paid for interest rate cap agreements						(1,186)					(1,186)			(1,186)		0	(1,186)	0
Deferred taxes			(569)			673			0	(5,737)	1,592	91	(5,884)	1,611	(201)	2,350	11,299	(18,570)
Change in fair value of income tax receivable agreement	3,480	(1,736)	1,021	(3,585)	2,641	(4,517)	(12,565)	7,835		(715)	(1,876)	7,835	2,765	(5,461)	(4,730)	(2,673)	(7,234)	(1,286)
Non-cash charge related to derivative agreements			1			173			623	5	173	850	18	173	489	46	173	473
Non-cash rent charges			167			289			512	161	431	920	400	588	1,764	73	1,044	2,191
Loss (gain) on disposal of assets			12			57				18	(60)		(81)	(315)		80	(27)	857
Change in operating assets and liabilities, net of acquisitions:
Accounts receivable			2,313			4,363			(10,332)	7,753	12,551	(21,995)	13,965	8,951	(21,527)	13,118	17,568	(21,221)
Inventories			(1,464)			28			(1,224)	(1,870)	(284)	(499)	(1,716)	4	(177)	(6,799)	11	(385)
Prepaid expenses and other current assets			(166)			798			(65)	6,338	(4,546)	(1,237)	7,261	1,484	836	(2,340)	(6,353)	(4,768)
Other assets			(4,313)			(63)			(18)	(8,733)	(552)	692	(7,291)	(558)	44	(5,712)	(1,325)	(219)
Accounts payable			7,464			(6,522)			1,286	19,428	(2,943)	944	20,602	2,736	706	25,661	2,294	8,556
Accrued compensation and benefits			(1,825)			(3,011)			(1,008)	1,896	(449)	2,965	5,673	2,664	6,588	5,602	(118)	6,599
Accrued expenses and other liabilities			(156)			(6,013)			5,954	17,837	(6,340)	12,495	1,686	(5,346)	13,836	7,027	(1,797)	16,863
Cash provided by operating activities			21,009			16,523			36,578	58,479	51,810	89,229	83,871	97,373	141,898	106,404	128,548	172,206
Investing activities
Purchases of property, equipment and intangible assets			(9,851)			(6,406)			(16,396)	(18,418)	(14,053)	(34,221)	(29,074)	(24,780)	(46,659)	(44,960)	(36,073)	(61,432)
Proceeds from asset sales			2,500							2,500	550		2,502	1,075		2,502	2,325	0
Cash paid for acquisitions												(800)			(4,467)	(388)	(1,555)	(4,507)
Cash used in investing activities			(7,351)			(6,406)			(16,396)	(15,918)	(13,503)	(35,021)	(26,572)	(23,705)	(51,126)	(42,846)	(35,303)	(65,939)
Financing activities
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense												175,378			175,254	0	0	175,254
Net proceeds from issuance of long-term debt											267,564	60,000		267,564	60,000	0	267,564	60,000
Cash paid for financing costs											(3,914)	(1,350)		(3,914)	(1,350)	0	(3,914)	(1,350)
Proceeds on term loans, net of deferred financing costs			10,506			4,881			12,282	28,946	11,991	39,764	52,576	34,742	54,706	82,389	49,921	70,590
Payments on long-term debt			(13,060)			(9,689)			(7,462)	(33,198)	(286,525)	(255,806)	(59,903)	(312,800)	(266,040)	(90,428)	(327,331)	(275,243)
Dividends and dividend equivalents paid			(257)			(271)				(278)	(8,680)	(30,176)	(320)	(8,715)	(30,223)	(332)	(8,729)	(30,241)
Proceeds from exercise of stock options			336			30				396	536		1,157	683		1,398	2,380	170
Common stock repurchases for tax withholdings of net settlement of equity awards												(71)			(356)	(417)	0	(356)
Distributions to noncontrolling interests			(16,718)			(19,044)			(21,440)	(34,189)	(38,542)	(43,973)	(55,131)	(60,509)	(66,985)	(70,960)	(79,478)	(94,468)
Contributions from noncontrolling interests			1,730			1,710			1,884	2,520	2,887	4,441	3,645	3,847	6,576	7,739	6,522	7,470
Purchases of noncontrolling interests			(3,158)			(4,546)				(8,601)	(9,507)	(277)	(8,729)	(27,854)	(8,397)	(9,066)	(29,540)	(8,397)
Proceeds from sales of additional noncontrolling interests			92							92		142	178	66	199	229	66	227
Cash used in financing activities			(20,896)			(26,929)			(15,203)	(44,679)	(64,190)	(51,928)	(66,948)	(106,890)	(76,616)	(79,869)	(122,539)	(96,344)
(Decrease) increase in cash			(7,238)			(16,812)			4,979	(2,118)	(25,883)	2,280	(9,649)	(33,222)	14,156	(16,311)	(29,294)	9,923
Cash at beginning of year	69,493	64,373	71,611	75,022	84,093	100,905	93,262	95,961	90,982	71,611	100,905	90,982	71,611	100,905	90,982	71,611	100,905	90,982
Cash and restricted cash at end of year	61,962	69,493	64,373	67,683	75,022	84,093	105,138	93,262	95,961	69,493	75,022	93,262	61,962	67,683	105,138	55,300	71,611	100,905
Supplemental Disclosure of Cash Flow Information
Cash paid for income taxes																2,635	1,885	16,095
Cash paid for interest																30,504	26,812	32,499
As Previously Reported
Operating activities
Net income	18,294	2,277	13,713	26,672	16,391	12,902	36,046	13,042	22,557	15,990	29,293	35,599	34,284	55,965	71,645		75,683	88,205
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization			9,623			9,074			7,677	19,437	18,456	15,929	29,460	27,894	24,616		37,634	33,862
Amortization of discounts, fees and deferred financing costs			497			530			797	989	1,065	1,807	1,384	1,534	2,432		2,031	2,595
Loss on early extinguishment of debt					526			4,708			526	4,708		526	4,708		526	4,708
Stock-based compensation			1,264			10,088			386	2,927	13,731	10,565	4,174	14,762	23,238		15,872	40,285
Premium paid for interest rate cap agreements						(1,186)					(1,186)			(1,186)			(1,186)
Deferred taxes			0			673			67	(5,014)	729	(7,769)	(5,014)	730	(8,508)		8,455	(14,018)
Change in fair value of income tax receivable agreement	3,480	(1,736)	1,021	(3,585)	2,641	(4,517)	(12,565)	7,835		(715)	(1,876)	7,835	2,765	(5,461)	(4,730)		(7,234)	(1,286)
Non-cash charge related to derivative agreements			1			173			623	5	173	850	18	173	489		173	473
Non-cash rent charges			167			289			512	161	431	920	400	588	1,764		1,044	2,191
Loss (gain) on disposal of assets			250			57				279	190		342	(377)			(772)	857
Change in operating assets and liabilities, net of acquisitions:
Accounts receivable			(6,061)			3,632			1,088	(11,846)	3,286	15	(10,934)	(107)	(334)		1,465	(4,208)
Inventories			(2,977)			28			(1,224)	(1,870)	(284)	(499)	(1,717)	4	(177)		11	(385)
Prepaid expenses and other current assets			(457)			(3,870)			(152)	7,119	(9,637)	1,305	6,809	(1,425)	(1,171)		(7,936)	(7,226)
Other assets			(4,311)			(63)			(18)	(8,733)	(552)	692	(7,291)	(558)	44		(1,325)	(219)
Accounts payable			7,464			(6,522)			1,286	19,428	(2,943)	944	20,602	2,736	706		2,294	8,556
Accrued compensation and benefits			(1,825)			(3,011)			(1,008)	1,896	(449)	2,965	5,673	2,664	6,588		(118)	6,599
Accrued expenses and other liabilities			2,640			(1,755)			3,985	18,426	1,407	13,363	2,916	(1,090)	20,593		1,930	11,222
Cash provided by operating activities			21,009			16,522			36,576	58,479	52,360	89,229	83,871	97,372	141,903		128,547	172,211
Investing activities
Purchases of property, equipment and intangible assets			(9,851)			(6,406)			(16,396)	(18,418)	(14,053)	(34,221)	(29,074)	(24,780)	(46,659)		(36,073)	(61,432)
Proceeds from asset sales			2,500							2,500	0		2,502	1,075			2,325
Cash paid for acquisitions												(800)			(4,467)		(1,555)	(4,507)
Cash used in investing activities			(7,351)			(6,406)			(16,396)	(15,918)	(14,053)	(35,021)	(26,572)	(23,705)	(51,126)		(35,303)	(65,939)
Financing activities
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense												175,378			175,254			175,254
Net proceeds from issuance of long-term debt											267,564	60,000		267,564	60,000		267,564	60,000
Cash paid for financing costs											(3,914)	(1,350)		(3,914)	(1,350)		(3,914)	(1,350)
Proceeds on term loans, net of deferred financing costs			10,506			4,881			12,282	28,946	11,991	39,764	52,576	34,742	54,706		49,921	70,590
Payments on long-term debt			(13,060)			(9,689)			(7,462)	(33,198)	(286,525)	(255,806)	(59,903)	(312,800)	(266,040)		(327,331)	(275,243)
Dividends and dividend equivalents paid			(257)			(271)				(278)	(8,680)	(30,176)	(320)	(8,715)	(30,223)		(8,729)	(30,241)
Proceeds from exercise of stock options			336			30				396	536		1,157	683			2,380	170
Common stock repurchases for tax withholdings of net settlement of equity awards												(71)			(356)			(356)
Distributions to noncontrolling interests			(16,718)			(19,044)			(21,440)	(34,189)	(38,542)	(43,973)	(55,131)	(60,509)	(66,985)		(79,478)	(94,468)
Contributions from noncontrolling interests			1,730			1,710			1,884	2,520	2,887	4,441	3,645	3,847	6,576		6,522	7,470
Purchases of noncontrolling interests			(3,158)			(4,546)				(8,601)	(9,507)	(277)	(8,729)	(27,854)	(8,397)		(29,540)	(8,397)
Proceeds from sales of additional noncontrolling interests			92							92		142	178	66	199		66	227
Cash used in financing activities			(20,896)			(26,929)			(15,203)	(44,679)	(64,190)	(51,928)	(66,948)	(106,890)	(76,616)		(122,539)	(96,344)
(Decrease) increase in cash			(7,238)			(16,813)			4,977	(2,118)	(25,883)	2,280	(9,649)	(33,223)	14,161		(29,295)	9,928
Cash at beginning of year	69,503	64,383	71,621	75,033	84,103	100,916	93,268	95,965	90,988	71,621	100,916	90,988	71,621	100,916	90,988	71,621	100,916	90,988
Cash and restricted cash at end of year	61,972	69,503	64,383	67,693	75,033	84,103	105,149	93,268	95,965	69,503	75,033	93,268	61,972	67,693	105,149		71,621	100,916
Restatement Adjustments
Operating activities
Net income	(5,782)	(10,660)	(6,549)	(881)	(6,632)	(1,140)	71	8,127	9,433	(17,209)	(7,772)	17,560	(22,991)	(8,653)	17,631		(17,547)	13,461
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization			0			0			0	0	0	0	0	0	0		0	0
Amortization of discounts, fees and deferred financing costs			0			0			0	0	0	0	0	0	0		0	0
Loss on early extinguishment of debt					0			0			0	0		0	0		0	0
Stock-based compensation			0			0			0	0	0	0	0	0	0		0	0
Premium paid for interest rate cap agreements						0					0			0			0
Deferred taxes			(569)			0			(67)	(723)	863	7,860	(870)	881	8,307		2,844	(4,552)
Change in fair value of income tax receivable agreement	0	0	0	0	0	0	0	0		0	0	0	0	0	0		0	0
Non-cash charge related to derivative agreements			0			0			0	0	0	0	0	0	0		0	0
Non-cash rent charges			0			0			0	0	0	0	0	0	0		0	0
Loss (gain) on disposal of assets			(262)			0				(297)	(250)		(261)	62			745	0
Change in operating assets and liabilities, net of acquisitions:
Accounts receivable			8,374			731			(11,420)	19,599	9,265	(22,010)	24,899	9,058	(21,193)		16,103	(17,013)
Inventories			1,513			0			0	0	0	0	1	0	0		0	0
Prepaid expenses and other current assets			291			4,668			87	(781)	5,091	(2,542)	452	2,909	2,007		1,583	2,458
Other assets			(2)			0			0	0	0	0	0	0	0		0	0
Accounts payable			0			0			0	0	0	0	0	0	0		0	0
Accrued compensation and benefits			0			0			0	0	0	0	0	0	0		0	0
Accrued expenses and other liabilities			(2,796)			(4,258)			1,969	(589)	(7,747)	(868)	(1,230)	(4,256)	(6,757)		(3,727)	5,641
Cash provided by operating activities			0			1			2	0	(550)	0	0	1	(5)		1	(5)
Investing activities
Purchases of property, equipment and intangible assets			0			0			0	0	0	0	0	0	0		0	0
Proceeds from asset sales			0							0	550		0	0			0
Cash paid for acquisitions												0			0		0	0
Cash used in investing activities			0			0			0	0	550	0	0	0	0		0	0
Financing activities
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense												0			0			0
Net proceeds from issuance of long-term debt											0	0		0	0		0	0
Cash paid for financing costs											0	0		0	0		0	0
Proceeds on term loans, net of deferred financing costs			0			0			0	0	0	0	0	0	0		0	0
Payments on long-term debt			0			0			0	0	0	0	0	0	0		0	0
Dividends and dividend equivalents paid			0			0				0	0	0	0	0	0		0	0
Proceeds from exercise of stock options			0			0				0	0		0	0			0	0
Common stock repurchases for tax withholdings of net settlement of equity awards												0			0			0
Distributions to noncontrolling interests			0			0			0	0	0	0	0	0	0		0	0
Contributions from noncontrolling interests			0			0			0	0	0	0	0	0	0		0	0
Purchases of noncontrolling interests			0			0				0	0	0	0	0	0		0	0
Proceeds from sales of additional noncontrolling interests			0							0		0	0	0	0		0	0
Cash used in financing activities			0			0			0	0	0	0	0	0	0		0	0
(Decrease) increase in cash			0			1			2	0	0	0	0	1	(5)		1	(5)
Cash at beginning of year	(10)	(10)	(10)	(11)	(10)	(11)	(6)	(4)	(6)	(10)	(11)	(6)	(10)	(11)	(6)	$ (10)	(11)	(6)
Cash and restricted cash at end of year	$ (10)	$ (10)	$ (10)	$ (10)	$ (11)	$ (10)	$ (11)	$ (6)	$ (4)	$ (10)	$ (11)	$ (6)	$ (10)	$ (10)	$ (11)		$ (10)	$ (11)

Initial Public Offering (Detail

Initial Public Offering (Details) - USD ($)	Apr. 26, 2016	Apr. 20, 2016	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Mar. 31, 2017	Apr. 30, 2016	Apr. 07, 2016	Mar. 31, 2016	Jan. 01, 2016
Initial Public Offering
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense				$ 175,378,000		$ 175,254,000	$ 0	$ 0	$ 175,254,000
Amendment of Certificate of Incorporation
Common stock, shares authorized (in shares)			300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000		300,000,000	300,000,000
Common stock, par value (in USD per share)			$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01		$ 0.01	$ 0.01
Stock split ratio	2.29
Clinic Loan Assignment and Term Loan Holdings LLC Distribution
Assigned clinic loans							$ 5,078,000	$ 11,082,000	$ 19,768,000
Period of weighted average maturity, clinic loans							11 months
Weighted average interest rate, clinic loans							5.12%
Amendments to and Repayment of Credit Facilities, Income Tax Receivable Agreement and Special Dividends and Stock Option Modification
Proceeds from term loans, net of deferred financing costs			$ 3,914,000	$ 1,350,000	$ 3,914,000	$ 1,350,000	$ 0	3,914,000	1,350,000
Write-off of deferred financing fees	$ 4,708,000
Percentage tax savings payable to pre-IPO stockholders	85.00%
Estimated liability based on fair value of tax receivable agreement		$ 23,400,000					4,952,000
Financial instrument fair value							3,700,000	7,500,000	21,200,000					$ 23,400,000			$ 0
Accrued but unpaid obligations under tax receivable agreement							1,252,000
Payments on tax receivable agreement							6,376,000	878,000
Cash dividend (in dollars per share)	$ 1.3
Cash dividends declared per share (in USD per share)	$ 28,886,000
Unrecognized non-cash compensation costs	$ 38,877,000
Compensation costs recognition period, after plan modifications	12 months
Stock compensation expense							5,721,000	15,872,000	40,298,000
Second Lien Credit Agreement
Initial Public Offering
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense	$ 165,635,000
First Lien Credit Agreement
Initial Public Offering
Transaction costs	1,350,000
Amendments to and Repayment of Credit Facilities, Income Tax Receivable Agreement and Special Dividends and Stock Option Modification
Increase in borrowing capacity	50,000,000
Aggregate amount of borrowing capacity	$ 100,000,000
Interest rate margin increase	0.25%
Proceeds from term loans, net of deferred financing costs	$ 2,700,000						1,350,000
Term loans
Amendments to and Repayment of Credit Facilities, Income Tax Receivable Agreement and Special Dividends and Stock Option Modification
Increase in borrowing capacity	$ 60,000,000
Guaranteed Clinic Loan
Clinic Loan Assignment and Term Loan Holdings LLC Distribution
Clinic loan guarantee							2,813,000	5,854,000	10,473,000
IPO
Initial Public Offering
Number of shares sold in public offering (in shares)	8,625,000
Share price (in USD per share)	$ 22
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense	$ 176,942,000
Transaction costs								2,239,000
Amendments to and Repayment of Credit Facilities, Income Tax Receivable Agreement and Special Dividends and Stock Option Modification
Stock compensation due to modification								$ 11,749,000	36,368,000
Stock compensation expense									$ 586,000
Vested Option Stockholders
Amendments to and Repayment of Credit Facilities, Income Tax Receivable Agreement and Special Dividends and Stock Option Modification
Equivalent adjustments in the form of cash dividend equivalent payments (in dollars per share)	$ 1.3
Equitable adjustments in the form of cash dividend equivalent payments							5,341,000
Vested Option Stockholders | Term Loan Holdings LLC
Amendments to and Repayment of Credit Facilities, Income Tax Receivable Agreement and Special Dividends and Stock Option Modification
Equitable adjustments in the form of cash dividend equivalent payments							$ 2,524,000
Unvested Option Stockholders
Amendments to and Repayment of Credit Facilities, Income Tax Receivable Agreement and Special Dividends and Stock Option Modification
Equitable adjustments in the form of cash dividend equivalent payments	$ 1,385,000
Minimum
Clinic Loan Assignment and Term Loan Holdings LLC Distribution
Interest rate							4.25%
Minimum | Term loans
Clinic Loan Assignment and Term Loan Holdings LLC Distribution
Interest rate							3.31%
Maximum
Clinic Loan Assignment and Term Loan Holdings LLC Distribution
Interest rate							8.08%
Maximum | Term loans
Clinic Loan Assignment and Term Loan Holdings LLC Distribution
Interest rate							7.98%

Cash (Details)

Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Cash and Cash Equivalents [Abstract]
Cash	$ 55,200	$ 61,862	$ 69,393	$ 64,273	$ 71,511	$ 67,583	$ 74,922	$ 83,993	$ 100,905	$ 105,138	$ 93,262	$ 95,961
Restricted cash included in other long-term assets	100				100				0
Total cash and restricted cash shown in the statement of cash flows	$ 55,300	$ 61,962	$ 69,493	$ 64,373	$ 71,611	$ 67,683	$ 75,022	$ 84,093	$ 100,905	$ 105,138	$ 93,262	$ 95,961	$ 90,982

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Medicare recovery claims	$ 10,622				$ 10,744				$ 9,224
Prepaid expenses and other	17,505				14,254				9,274
Prepaid expenses and other current assets	$ 28,127	$ 18,716	$ 19,087	$ 25,277	$ 24,998	$ 17,133	$ 23,150	$ 18,217	$ 18,498	$ 12,914	$ 14,902	$ 19,395

Acquisitions and Divestitures -

Acquisitions and Divestitures - Acquisitions (Details) $ in Thousands	Sep. 01, 2016dialysis_center	Dec. 31, 2017USD ($)dialysis_center	Dec. 31, 2018USD ($)	Nov. 01, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Number of dialysis centers not operational prior to acquisition | dialysis_center	1
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill		$ 573,145	$ 571,339		$ 571,339	$ 571,339	$ 571,341	$ 572,420	$ 572,800	$ 573,092	$ 573,092	$ 573,052	$ 569,876	$ 569,261	$ 569,264
Goodwill expected to be deductible for tax purposes			$ 647								3,723
Dialysis Center in California
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Property and equipment				$ 329
Other assets				59
Cash consideration paid				$ 388
Acquisition 2017
Business Acquisition [Line Items]
Number of dialysis centers | dialysis_center		2
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Property and equipment		$ 737
Noncompete agreements		93
Goodwill		725
Cash consideration paid		$ 1,555
Acquisition 2016
Business Acquisition [Line Items]
Number of dialysis centers | dialysis_center	2
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Property and equipment											400
Noncompete agreements											268
Goodwill											3,839
Cash consideration paid											$ 4,507

Acquisitions and Divestitures_2

Acquisitions and Divestitures - Divestitures (Details) $ in Thousands	Aug. 01, 2017USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)dialysis_clinic	Mar. 01, 2018	Jun. 02, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reduction of goodwill on sale of dialysis clinics			$ 1,806	$ 672
Dialysis Clinic In Florida | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest disposed	100.00%				100.00%
Proceeds from sale of dialysis clinics	$ 1,075	$ 2,500
Gain (loss) on sale of dialysis clinics			262
Reduction of goodwill on sale of dialysis clinics			$ 1,806
Dialysis Clinic In Massachusetts | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest disposed						100.00%
Dialysis Clinic In Massachusetts And Florida | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on sale of dialysis clinics				615
Reduction of goodwill on sale of dialysis clinics				563
Four Dialysis Clinics | Disposal Group, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on sale of dialysis clinics				(107)
Reduction of goodwill on sale of dialysis clinics				$ 109
Number of dialysis clinics disposed | dialysis_clinic				4

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfers between Levels 1, 2 and 3	$ 0	$ 0
First lien term loans
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Carrying amount of debt	433,400,000	437,800,000	$ 433,758,000
Fair value of debt	$ 424,732,000	$ 436,158,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of fair value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
FAIR VALUE MEASUREMENTS
Noncontrolling interests subject to put provisions	$ 129,099	$ 130,438	$ 150,049
Recurring basis
FAIR VALUE MEASUREMENTS
Total Assets	1,231	301
Total Liabilities	3,700	8,101
Noncontrolling interests subject to put provisions	129,099	130,438	150,049
Recurring basis | Interest rate derivative agreements (included in Prepaid expenses and other current assets)
FAIR VALUE MEASUREMENTS
Total Assets	836	46	7
Recurring basis | Interest rate derivative agreements (included in Other long-term assets)
FAIR VALUE MEASUREMENTS
Total Assets	395	255
Recurring basis | Tax Receivable Agreement Liability (included in Income tax receivable agreement payable)
FAIR VALUE MEASUREMENTS
Tax Receivable Agreement Liability (included in Income tax receivable agreement payable)	3,700	7,500
Interest rate swap agreements liability			21,200
Recurring basis | Interest rate derivative agreements (included in Accrued expense and other current liabilities)
FAIR VALUE MEASUREMENTS
Interest rate swap agreements liability		403
Recurring basis | Interest rate derivative agreements (included in Other long-term liabilities)
FAIR VALUE MEASUREMENTS
Interest rate swap agreements liability		198
Recurring basis | Level 1
FAIR VALUE MEASUREMENTS
Total Assets	0	0
Total Liabilities	0	0
Noncontrolling interests subject to put provisions	0	0	0
Recurring basis | Level 1 | Interest rate derivative agreements (included in Prepaid expenses and other current assets)
FAIR VALUE MEASUREMENTS
Total Assets	0	0	0
Recurring basis | Level 1 | Interest rate derivative agreements (included in Other long-term assets)
FAIR VALUE MEASUREMENTS
Total Assets	0	0
Recurring basis | Level 1 | Tax Receivable Agreement Liability (included in Income tax receivable agreement payable)
FAIR VALUE MEASUREMENTS
Tax Receivable Agreement Liability (included in Income tax receivable agreement payable)	0	0
Interest rate swap agreements liability			0
Recurring basis | Level 1 | Interest rate derivative agreements (included in Accrued expense and other current liabilities)
FAIR VALUE MEASUREMENTS
Interest rate swap agreements liability		0
Recurring basis | Level 1 | Interest rate derivative agreements (included in Other long-term liabilities)
FAIR VALUE MEASUREMENTS
Interest rate swap agreements liability		0
Recurring basis | Level 2
FAIR VALUE MEASUREMENTS
Total Assets	1,231	301
Total Liabilities	0	601
Noncontrolling interests subject to put provisions	0	0	0
Recurring basis | Level 2 | Interest rate derivative agreements (included in Prepaid expenses and other current assets)
FAIR VALUE MEASUREMENTS
Total Assets	836	46	7
Recurring basis | Level 2 | Interest rate derivative agreements (included in Other long-term assets)
FAIR VALUE MEASUREMENTS
Total Assets	395	255
Recurring basis | Level 2 | Tax Receivable Agreement Liability (included in Income tax receivable agreement payable)
FAIR VALUE MEASUREMENTS
Tax Receivable Agreement Liability (included in Income tax receivable agreement payable)	0	0
Interest rate swap agreements liability			0
Recurring basis | Level 2 | Interest rate derivative agreements (included in Accrued expense and other current liabilities)
FAIR VALUE MEASUREMENTS
Interest rate swap agreements liability		403
Recurring basis | Level 2 | Interest rate derivative agreements (included in Other long-term liabilities)
FAIR VALUE MEASUREMENTS
Interest rate swap agreements liability		198
Recurring basis | Level 3
FAIR VALUE MEASUREMENTS
Total Assets	0	0
Total Liabilities	3,700	7,500
Noncontrolling interests subject to put provisions	129,099	130,438	150,049
Recurring basis | Level 3 | Interest rate derivative agreements (included in Prepaid expenses and other current assets)
FAIR VALUE MEASUREMENTS
Total Assets	0	0	0
Recurring basis | Level 3 | Interest rate derivative agreements (included in Other long-term assets)
FAIR VALUE MEASUREMENTS
Total Assets	0	0
Recurring basis | Level 3 | Tax Receivable Agreement Liability (included in Income tax receivable agreement payable)
FAIR VALUE MEASUREMENTS
Tax Receivable Agreement Liability (included in Income tax receivable agreement payable)	$ 3,700	7,500
Interest rate swap agreements liability			$ 21,200
Recurring basis | Level 3 | Interest rate derivative agreements (included in Accrued expense and other current liabilities)
FAIR VALUE MEASUREMENTS
Interest rate swap agreements liability		0
Recurring basis | Level 3 | Interest rate derivative agreements (included in Other long-term liabilities)
FAIR VALUE MEASUREMENTS
Interest rate swap agreements liability		$ 0

Fair Value Measurements - Fair

Fair Value Measurements - Fair value rollforward of tax receivable agreement liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 7,500	$ 21,200
Options exercised and dividend equivalent payment vesting	(1,127)	(6,466)	$ (914)
Total realized/unrealized gains:
Included in earnings and reported as Change in fair value of income tax receivable agreement	(2,673)	(7,234)	(1,286)
Balance at end of period	$ 3,700	$ 7,500	$ 21,200

Property and Equipment (Details

Property and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016
Property and Equipment
Property and equipment, gross	$ 379,971,000	$ 335,927,000	$ 291,360,000
Less accumulated depreciation	(199,703,000)	(167,390,000)	(121,242,000)
Property and equipment, net	180,268,000	168,537,000	170,118,000	$ 168,346,000	$ 167,621,000	$ 168,682,000	$ 166,890,000	$ 165,495,000	$ 167,338,000	$ 165,132,000	$ 160,887,000	$ 151,204,000
Depreciation of property and equipment	39,004,000	37,045,000	32,837,000
Cost of assets under capital leases	6,381,000	0	0
Accumulated depreciation for assets under capital leases	213,000
Current assets held for sale	577,000	0	0
Land
Property and Equipment
Property and equipment, gross	2,030,000	2,030,000	2,203,000
Buildings and improvements
Property and Equipment
Property and equipment, gross	8,197,000	2,904,000	3,425,000
Leasehold improvements
Property and Equipment
Property and equipment, gross	201,445,000	178,569,000	154,783,000
Equipment and information systems
Property and Equipment
Property and equipment, gross	162,750,000	145,514,000	125,813,000
Construction in progress
Property and Equipment
Property and equipment, gross	5,549,000	$ 6,910,000	$ 5,136,000
Certain Clinics In Maryland | Disposal Group, Held-for-sale, Not Discontinued Operations | Property, Plant and Equipment
Property and Equipment
Current assets held for sale	$ 477,000

Intangible Assets and Goodwil_2

Intangible Assets and Goodwill - Schedule of intangible assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible assets:
Gross intangible assets	$ 27,500	$ 27,453	$ 27,781
Less accumulated amortization	(24,206)	(23,419)	(23,489)
Net intangible assets subject to amortization	3,294	4,034	4,292
Total deferred financing costs and intangible assets	24,628	25,368	25,626
Amortization of intangible assets	798	589	1,025
Indefinite-lived trademarks and trade name
Intangible assets:
Indefinite‑lived trademarks and trade name	21,334	21,334	21,334
Noncompete agreements
Intangible assets:
Noncompete agreements	24,370	24,380	24,928
Other intangible assets
Intangible assets:
Other intangible assets	$ 3,130	$ 3,073	$ 2,853

Intangible Assets and Goodwil_3

Intangible Assets and Goodwill - Estimated annual amortization expense (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Estimated annual amortization expense related to amortizable intangible
2019	$ 747
2020	665
2021	615
2022	470
2023	220
Thereafter	577
Net intangible assets subject to amortization	$ 3,294	$ 4,034	$ 4,292

Intangible Assets and Goodwil_4

Intangible Assets and Goodwill - Changes in the value of goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill
Balance at the beginning	$ 573,145	$ 573,092	$ 569,264
Acquisitions		725	3,839
Subsequent adjustment for prior year acquisition			(11)
Divestitures	(1,806)	(672)
Balance at the end	$ 571,339	$ 573,145	$ 573,092

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016
Accrued compensation and benefits:
Accrued compensation	$ 22,480				$ 17,987				$ 18,077
Accrued vacation pay	12,107				10,998				11,026
Accrued compensation and benefits	34,587	$ 34,658	$ 30,881	$ 27,160	28,985	$ 31,767	$ 28,654	$ 26,092	29,103	$ 29,092	$ 25,469	$ 21,496
Accrued expenses and other current liabilities:
Due to payors	26,659				28,935				32,902
Income tax payable	13,618				14,654				17,851
Other	13,198				20,986				12,269
Accrued Settlement	7,641				0				0
Accrued expenses and other current liabilities	$ 61,116	$ 56,538	$ 62,950	$ 63,790	$ 64,575	$ 57,199	$ 70,695	$ 58,559	$ 63,022	$ 59,388	$ 56,818	$ 45,210

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Thousands	Dec. 31, 2018USD ($)
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Total assets of VIEs	$ 16,669
Total liabilities of VIEs	$ 9,038

Noncontrolling Interests Subj_3

Noncontrolling Interests Subject to Put Provisions (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
NONCONTROLLING INTERESTS SUBJECT TO PUT PROVISIONS
Potential obligations under time based put provisions	$ 101,115	$ 97,650	$ 108,774
Potential additional obligations under event based put provisions	27,984	32,788	41,275
Redemption value	11,221	12,283	20,491
Estimated fair values for accounting purposes	2,672	5,970	10,424
Difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests	8,549	6,313	10,067
Noncontrolling interest subject to put provisions - estimated fair values	120,550	124,125	139,982
Noncontrolling interests subject to put provisions - maximum redemption value	129,099	130,438	150,049
Total change in fair value of noncontrolling interests subject to put provisions - maximum redemption	7,397	(9,617)	(27,482)
Noncontrolling Interests subject to put provisions
NONCONTROLLING INTERESTS SUBJECT TO PUT PROVISIONS
Change in estimated fair values for accounting purposes	(9,963)	(1,886)	17,415
Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests	2,566	11,503	10,067
Total change in fair value of noncontrolling interests subject to put provisions - maximum redemption	$ (7,397)	$ 9,617	$ 27,482
Measurement Input, Discount Rate | Minimum
NONCONTROLLING INTERESTS SUBJECT TO PUT PROVISIONS
Weighted average cost of capital	0.1450
Measurement Input, Discount Rate | Maximum
NONCONTROLLING INTERESTS SUBJECT TO PUT PROVISIONS
Weighted average cost of capital	0.2050

Changes in Ownership Interest_3

Changes in Ownership Interest in Consolidated Subsidiaries (Details) - USD ($) $ in Thousands	3 Months Ended											6 Months Ended			9 Months Ended			12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CHANGES IN OWNERSHIP INTEREST IN CONSOLIDATED SUBSIDIARIES
Net (loss) income attributable to American Renal Associates Holdings, Inc.	$ (572)	$ (734)	$ (23,659)	$ (3,802)	$ (4,898)	$ 7,496	$ (5,073)	$ (2,122)	$ 12,772	$ (7,073)	$ 6,521	$ (27,461)	$ (7,195)	$ (552)	$ (28,195)	$ 301	$ 12,220	$ (28,767)	$ (4,597)	$ 3,146
(Decrease) increase in paid-in capital for the sales of noncontrolling interest																		(891)	231	99
Decrease in paid-in capital for the purchase of noncontrolling interest and adjustments to ownership interest																		(6,645)	(7,566)	(7,680)
Net transfers to noncontrolling interests																		(7,536)	(7,335)	(7,581)
Net loss attributable to American Renal Associates Holdings, Inc., net of transfers to noncontrolling interests																		$ (36,303)	$ (11,932)	$ (4,435)

Debt - Schedule of long term-te

Debt - Schedule of long term-term debt (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016
LONG-TERM DEBT
Capital Lease Obligations	$ 6,706				$ 0				$ 0
Long-term debt, gross and lease obligation, gross	568,439				569,619				574,662
Less: discounts and fees, net of accumulated amortization	(8,073)				(9,531)				(4,330)
Less: current maturities	(42,855)	$ (47,206)	$ (46,660)	$ (45,121)	(44,534)	$ (44,189)	$ (45,711)	$ (45,559)	(48,274)	$ (43,582)	$ (40,579)	$ (27,171)
Long-term debt excluding current maturities	517,511	$ 506,750	$ 509,983	$ 512,822	515,554	$ 514,846	$ 516,442	$ 520,364	522,058	$ 520,017	$ 517,798	$ 661,369
Loans Payable
LONG-TERM DEBT
Long-term debt, gross	5,078				11,082				19,768
Other Term Loans
LONG-TERM DEBT
Long-term debt, gross	113,866				114,536				98,735
Other Line Of Credit
LONG-TERM DEBT
Long-term debt, gross	1,849				3,600				19,360
Other
LONG-TERM DEBT
Long-term debt, gross	$ 2,040				2,601				3,041
Interest rate	4.07%
Minimum
LONG-TERM DEBT
Interest rate	4.25%
Minimum | Term Loans
LONG-TERM DEBT
Interest rate	3.31%
Minimum | Lines of Credit
LONG-TERM DEBT
Interest rate	4.13%
Maximum
LONG-TERM DEBT
Interest rate	8.08%
Maximum | Term Loans
LONG-TERM DEBT
Interest rate	7.98%
Maximum | Lines of Credit
LONG-TERM DEBT
Interest rate	5.13%
2017 Credit Agreement | Term Loans
LONG-TERM DEBT
Long-term debt, gross	$ 433,400				437,800				433,758
Interest rate	5.77%
Revolving Credit Facility | 2017 Credit Agreement | Lines of Credit
LONG-TERM DEBT
Long-term debt, gross	$ 5,500				$ 0				$ 0

Debt Debt - Scheduled maturitie

Debt Debt - Scheduled maturities of long-term debt (Details) $ in Thousands	Dec. 31, 2018USD ($)
Debt Disclosure [Abstract]
2019	$ 43,022
2020	35,761
2021	26,461
2022	23,956
2023	15,128
Thereafter	424,111
Total long-term debt	$ 568,439

Debt - Narrative (Details)

Debt - Narrative (Details)

Sep. 04, 2019

Apr. 26, 2019

Jun. 22, 2017USD ($)

Apr. 26, 2016USD ($)

Sep. 04, 2019USD ($)

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Jun. 30, 2019USD ($)

Sep. 30, 2018USD ($)

Jun. 30, 2018USD ($)

Mar. 31, 2018USD ($)

Sep. 30, 2017USD ($)

Jun. 30, 2017USD ($)

Mar. 31, 2017USD ($)interest_rate_cap_agreement

Sep. 30, 2016USD ($)

Jun. 30, 2016USD ($)

Mar. 31, 2016USD ($)

LONG-TERM DEBT

Write-off of deferred financing fees

$ 4,708,000

Long-term debt excluding current maturities

$ 517,511,000

$ 515,554,000

$ 522,058,000

$ 506,750,000

$ 509,983,000

$ 512,822,000

$ 514,846,000

$ 516,442,000

$ 520,364,000

$ 520,017,000

$ 517,798,000

$ 661,369,000

Revolving Credit Facility

LONG-TERM DEBT

Revolving credit facility borrowings outstanding

$ 5,500,000

Revolving credit facility commitment fee as a percentage

0.50%

Interest rate swap agreements

LONG-TERM DEBT

Unrealized pre-tax (gain) loss of the Swaps

$ (668,000)

2017 Credit Agreement

LONG-TERM DEBT

Mandatory principal payment

$ 4,400,000

Costs associated with refinancing activities

$ 9,259,000

Transaction costs

717,000

Debt discounts

4,628,000

Deferred debt issuance costs

3,914,000

Write-off of deferred financing fees

526,000

Lines of Credit | 2017 Credit Agreement | Revolving Credit Facility

LONG-TERM DEBT

Revolving credit facility borrowings outstanding

$ 5,500,000

Revolving credit facility maximum borrowing capacity

100,000,000

Incremental accordion facility amount

$ 125,000,000

Incremental accordion feature percentage of EBITDA

100.00%

Revolving credit facility commitment fee as a percentage

0.50%

Interest rate at period end

4.86%

Lines of Credit | 2017 Credit Agreement, First Amendment | Revolving Credit Facility

LONG-TERM DEBT

Long-term debt excluding current maturities

$ 4,200,000

Term loans | 2017 Credit Agreement

LONG-TERM DEBT

Debt face amount

$ 440,000,000

Interest rate

5.77%

Required prepayment

$ 0

Quarterly installment payment

$ 1,100,000

Term loans | 2017 Credit Agreement | Federal funds effective rate

LONG-TERM DEBT

Applicable margin

0.50%

Term loans | 2017 Credit Agreement | Eurodollar base rate

LONG-TERM DEBT

Applicable margin

1.00%

Term loans | 2017 Credit Agreement | Alternate base rate

LONG-TERM DEBT

Applicable margin

2.25%

Term loans | 2017 Credit Agreement | LIBOR

LONG-TERM DEBT

Applicable margin

3.25%

Term loans | First Lien Credit Agreement, Second Amendment | Alternate base rate

LONG-TERM DEBT

Applicable margin

2.25%

Term loans | First Lien Credit Agreement, Second Amendment | LIBOR

LONG-TERM DEBT

Applicable margin

3.25%

Term loans | Term B Loans due September 2019

LONG-TERM DEBT

Debt face amount

440,000,000

Minimum

LONG-TERM DEBT

Interest rate

4.25%

Minimum | Lines of Credit

LONG-TERM DEBT

Interest rate

4.13%

Minimum | Term loans

LONG-TERM DEBT

Interest rate

3.31%

Maximum

LONG-TERM DEBT

Interest rate

8.08%

Maximum | Lines of Credit

LONG-TERM DEBT

Interest rate

5.13%

Maximum | Term loans

LONG-TERM DEBT

Interest rate

7.98%

Cash flow hedge | Designated as a hedge | Interest rate swap agreements

LONG-TERM DEBT

Interest rate swap agreements notional amount

133,000,000

Unrealized pre-tax (gain) loss of the Swaps

$ (892,000)

601,000

Cash flow hedge | Designated as a hedge | Interest rate cap agreements

LONG-TERM DEBT

Interest rate swap agreements notional amount

$ 147,000,000

Number of interest rate swap agreements | interest_rate_cap_agreement

2

Unrealized pre-tax (gain) loss of the Swaps

$ 586,000

$ 884,000

Subsequent Event | 2017 Credit Agreement, First Amendment

LONG-TERM DEBT

Financial covenant, net leverage ratio, maximum

7

Subsequent Event | 2017 Credit Agreement, First Amendment | Revolving Credit Facility

LONG-TERM DEBT

Fees related to debt amendment

$ 6,021,000

Subsequent Event | Lines of Credit | 2017 Credit Agreement, First Amendment | Revolving Credit Facility

LONG-TERM DEBT

Revolving credit facility commitment fee as a percentage

0.50%

Maximum cash and cash equivalent for debt issuance

$ 75,000,000

Financial covenant, net leverage ratio, maximum

6

Subsequent Event | Lines of Credit | 2017 Credit Agreement, First Amendment | Eurodollar base rate | Revolving Credit Facility

LONG-TERM DEBT

Applicable margin

5.25%

Subsequent Event | Lines of Credit | 2017 Credit Agreement, First Amendment | Base Rate | Revolving Credit Facility

LONG-TERM DEBT

Applicable margin

4.25%

Subsequent Event | Lines of Credit | 2017 Credit Agreement, First Amendment | Alternate Base Rate Or London Interbank Offered Rate (LIBOR) | Revolving Credit Facility

LONG-TERM DEBT

Applicable margin, increase

1.75%

Subsequent Event | Term loans | 2017 Credit Agreement, First Amendment | Federal funds effective rate

LONG-TERM DEBT

Applicable margin

0.50%

Subsequent Event | Term loans | 2017 Credit Agreement, First Amendment | Eurodollar base rate

LONG-TERM DEBT

Applicable margin

5.00%

1.00%

Subsequent Event | Term loans | 2017 Credit Agreement, First Amendment | Alternate base rate

LONG-TERM DEBT

Applicable margin

4.50%

Subsequent Event | Term loans | 2017 Credit Agreement, First Amendment | LIBOR

LONG-TERM DEBT

Applicable margin

5.50%

Subsequent Event | Term loans | 2017 Credit Agreement, First Amendment | Base Rate

LONG-TERM DEBT

Applicable margin

4.00%

Debt Instrument, Redemption, Period One | Subsequent Event | Term loans | 2017 Credit Agreement, First Amendment

LONG-TERM DEBT

Debt redemption price, percentage

1.00%

Debt Instrument, Redemption, Period Two | Subsequent Event | Term loans | 2017 Credit Agreement, First Amendment

LONG-TERM DEBT

Debt redemption price, percentage

2.00%

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Leased Assets [Line Items]
Rental expense	$ 30,843	$ 28,546	$ 25,346
Amortization expenses for assets purchased under capital leases	213
Rental income under subleases	1,709	1,515	1,439
Future rental receipts due from related party	6,581
Noncontrolling interests not subject to put provisions
Operating Leased Assets [Line Items]
Rental expense	10,778	10,160	8,238
Rental income under subleases	$ 963	$ 853	$ 813
Minimum
Operating Leased Assets [Line Items]
Lease agreements cover periods	5 years
Lease agreements renewal option period	5 years
Maximum
Operating Leased Assets [Line Items]
Lease agreements cover periods	15 years
Lease agreements renewal option period	10 years

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2018USD ($)
Operating Leases
2018	$ 31,311
2019	29,608
2020	27,597
2021	25,132
2022	20,363
Thereafter	61,085
Total operating leases	195,096
Less: Sublease Receipts
2018	1,537
2019	1,551
2020	1,572
2021	1,592
2022	1,117
Thereafter	3,175
Total sublease receipts	10,544
Net Operating Leases
2018	29,774
2019	28,057
2020	26,025
2021	23,540
2022	19,246
Thereafter	57,910
Total net lease obligation	184,552
Capital Leases
2019	876
2020	930
2021	940
2022	950
2023	963
Thereafter	6,286
Total minimum lease payments	10,945
Less: amount representing interest	4,239
Present value of net minimum capital lease payments	6,706
Less: current installments of obligations under capital leases	302
Long-term capital lease obligation	$ 6,404

Income Taxes - Provision (benef

Income Taxes - Provision (benefit) for income taxes (Details) - USD ($) $ in Thousands	3 Months Ended									6 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal																$ (112)	$ (2,000)	$ 17,432
State																657	173	3,617
Current income tax																545	(1,827)	21,049
Deferred:
Federal																1,348	9,435	(15,873)
State																1,003	1,863	(2,697)
Deferred income tax																2,351	11,298	(18,570)
Total provision for income taxes	$ (124)	$ (2,327)	$ (3,069)	$ 3,763	$ (1,837)	$ (3,180)	$ (983)	$ 1,208	$ 4,499	$ (5,396)	$ (5,017)	$ 5,707	$ (5,520)	$ (1,254)	$ 4,724	$ 2,896	$ 9,471	$ 2,479

Income Taxes - Significant comp

Income Taxes - Significant components of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Net operating loss and contribution carryforwards	$ 5,542	$ 5,541	$ 7,092
Legal settlement (Note 23)	5,065	0	0
Accrued expenses	1,484	1,115	1,519
Stock-based compensation	9,417	9,708	16,568
Interest limitation	2,189	0	0
Other	165	165	250
Interest rate swap	0	379	66
Deferred tax assets:	23,862	16,908	25,495
Valuation allowance	(12,420)	(5,414)	0
Total deferred tax assets	11,442	11,494	25,495
Investment in joint ventures	(9,784)	(7,254)	(8,039)
Goodwill and intangible amortization	(3,400)	(3,331)	(4,943)
Depreciation	(1,378)	(1,293)	(2,054)
Other	(49)	(38)	(110)
Total deferred tax liabilities	(14,611)	(11,916)	(15,146)
Net deferred tax (liabilities)	$ (3,169)	$ (422)
Net deferred tax assets			$ 10,349

Income Taxes Income Taxes - Nar

Income Taxes Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2016
Income Tax Disclosure [Abstract]
State loss carryforwards		$ 3,410
Charitable contribution carryforwards		20,510
Valuation allowance	$ 5,414	12,420	$ 0
Valuation allowance, deferred tax asset, increase (decrease)		7,006
Valuation allowance, deferred tax asset, increase, charitable contributions		1,042
Valuation allowance, deferred tax asset, decrease, charitable contributions benefits subject to expiration		1,041
Valuation allowance, deferred tax asset, increase, other		7,005
Tax cuts and jobs act, net income tax	2,700
Unrecognized tax benefits that would impact effective tax rate	9,245	6,633	11,020
Interest accrued on recognized tax benefits that would impact effective tax rate	$ 1,353	$ 2,511	$ 474

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the federal statutory rate (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income tax provision at federal statutory rate	21.00%	35.00%	35.00%
Increase (decrease) in tax resulting from:
State taxes, net of federal benefit	(2.90%)	0.60%	0.90%
Noncontrolling interests in passthrough entities	(44.00%)	(32.30%)	(33.40%)
Valuation allowance	33.00%	8.70%	0.00%
Other permanent items, net	4.80%	2.00%	(0.10%)
Effective income tax rate	11.90%	14.00%	2.40%

Income Taxes - Gross amounts of

Income Taxes - Gross amounts of unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
January 1	$ 21,077	$ 25,062	$ 15,833
Increase due to current year tax positions	0	0	9,229
Decrease due to prior year tax positions	(4,109)	(3,985)	0
December 31	$ 16,968	$ 21,077	$ 25,062

Loss Per Share (Details)

Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended											6 Months Ended			9 Months Ended			12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic and Diluted
Net (loss) income attributable to American Renal Associates Holdings, Inc.	$ (572)	$ (734)	$ (23,659)	$ (3,802)	$ (4,898)	$ 7,496	$ (5,073)	$ (2,122)	$ 12,772	$ (7,073)	$ 6,521	$ (27,461)	$ (7,195)	$ (552)	$ (28,195)	$ 301	$ 12,220	$ (28,767)	$ (4,597)	$ 3,146
Change in the difference between the redemption values and estimated fair values for accounting purposes of the related noncontrolling interests		(580)	(1,248)	497		559	(2,884)	(10,407)	(3,339)	(10,322)	0	(751)	(13,291)	(10,322)	(1,331)	(12,732)	(13,661)	(2,566)	(11,503)	(10,067)
Net income (loss) attributable to common shareholders		$ (1,314)	$ (24,907)	$ (3,305)		$ 8,055	$ (7,957)	$ (12,529)	$ 9,433	$ (17,395)	$ 6,521	$ (28,212)	$ (20,486)	$ (10,874)	$ (29,526)	$ (12,431)	$ (1,441)	$ (31,333)	$ (16,100)	$ (6,921)
Weighted-average common shares outstanding (in shares)		32,005,544	31,932,705	31,800,553		31,095,418	30,986,689	30,907,482	30,865,350	28,406,999	22,213,967	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297	31,965,844	31,081,824	28,118,673
Weighted-average common shares outstanding, assuming dilution (in shares)		32,005,544	31,932,705	31,800,553		33,833,822	30,986,689	30,907,482	31,436,814	28,406,999	22,785,670	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297	31,965,844	31,081,824	28,118,673
Loss per share, basic and diluted (in USD per share)																		$ (0.98)	$ (0.52)	$ (0.25)
Outstanding options excluded as impact would be antidilutive (in shares)																		3,442,048	1,894,340	572,097

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Mar. 31, 2018	Apr. 30, 2016	Mar. 31, 2014	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 26, 2016	Jan. 31, 2011	May 31, 2010
Contractual term				10 years
Aggregate intrinsic value of stock options exercised				$ 4,825	$ 10,974	$ 1,299
Unamortized stock-based compensation				$ 6,178
Weighted-average vesting period				3 years 5 months
Unrecognized non-cash compensation costs							$ 38,877
Minimum
Vesting period				3 years
Maximum
Vesting period				5 years
American Renal Holdings Inc. 2005 Equity Incentive Plan
Stock options to purchase outstanding (in shares)				11,120
Common stock reserved for issuance and remaining for future equity grants (in shares)				0
American Renal Associates Holdings, Inc. 2010 Stock Incentive Plan
Stock options to purchase outstanding (in shares)				3,859,143
Common stock reserved for issuance and remaining for future equity grants (in shares)				0					3,606,251
Authorized additional stock options (in shares)			1,627,258
American Renal Associates Holdings, Inc. 2011 Stock Option Plan for Nonemployee Directors
Stock options to purchase outstanding (in shares)				34,350
Common stock reserved for issuance and remaining for future equity grants (in shares)				0				100,000
2016 Omnibus Incentive Plan
Common stock reserved for issuance and remaining for future equity grants (in shares)				2,056,620
Authorized additional stock options (in shares)		4,000,000
Common stock | 2016 Omnibus Incentive Plan
Nonvested (in shares)				1,106,578
Restricted stock
Nonvested (in shares)				441,063	252,307
Unamortized stock-based compensation				$ 4,929
Awards granted (in shares)				359,691
Awards granted (in USD per share)				$ 22.18
Weighted-average vesting period				1 year 3 months 18 days
Fair value of restricted stock vested				$ 1,701	$ 440	$ 0
Restricted stock | 2016 Omnibus Incentive Plan
Nonvested (in shares)				441,063
Market and Performance Based Vesting
Unamortized stock-based compensation				$ 408
Performance and Time Based Vesting
Unamortized stock-based compensation				$ 5,771
Executive | Restricted stock
Vesting period	3 years
Awards granted (in shares)	95,000
Awards granted (in USD per share)	$ 22.33

Stock-Based Compensation - Equi

Stock-Based Compensation - Equity Grants, Assumptions and Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Total stock‑based compensation	$ 5,721	$ 15,872	$ 40,298
Income tax benefit	1,493	6,349	16,119
Patient care costs
Total stock‑based compensation	714	2,773	5,720
General and administrative
Total stock‑based compensation	$ 5,007	$ 13,099	$ 34,578

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions used for options granted (Details) - Stock option - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility			25.00%
Weighted average expected term in years	6 years	6 years
Expected annual dividend yield	0.00%	0.00%	0.00%
Weighted-average grant-date fair value (in USD per share)	$ 7.14	$ 5.52	$ 6.24
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	30.00%	30.00%
Weighted average expected term in years			6 years
Risk-free interest rate	2.74%	1.92%	1.20%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	35.00%	35.00%
Weighted average expected term in years			6 years 6 months
Risk-free interest rate	2.99%	2.26%	1.58%

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock option activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Options
Outstanding, beginning of period (in shares)	5,280,261
Granted (in shares)	296,286
Exercised (in shares)	(348,442)
Forfeited/Cancelled (in shares)	(216,914)
Outstanding, end of period (in shares)	5,011,191	5,280,261
Options vested and expected to vest, end of period (in shares)	5,011,191
Options exercisable, end of period (in shares)	3,172,792
Weighted-average exercise price
Options outstanding, weighted average exercise price, beginning of period (in USD per share)	$ 11.79
Granted, weighted average exercise price (in USD per share)	19.32
Exercised, weighted average exercise price (in USD per share)	5.17
Forfeited/Cancelled, weighted average exercise price (in USD per share)	16.50
Options outstanding, weighted average exercise price, end of period (in USD per share)	12.38	$ 11.79
Options vested and expected to vest, weighted average exercise price, end of period (in USD per share)	12.38
Options exercisable, weighted average exercise price, end of period (in USD per share)	$ 8.29
Weighted - average remaining contractual term (in years)
Options outstanding, weighted average remaining contractual term	4 years 11 months 28 days
Vested and expected to vest, weighted average remaining contractual term	4 years 11 months 28 days
Exercisable, weighted average remaining contractual term	3 years 11 months 24 days
Aggregate intrinsic value
Options outstanding, Aggregate intrinsic value	$ 17,056
Vested and expected to vest, Aggregate intrinsic value	17,056
Exercisable, Aggregate intrinsic value	17,056
Aggregate intrinsic value of stock options exercised	4,825	$ 10,974	$ 1,299
Unrecognized compensation costs	$ 6,178
Weighted average period	3 years 5 months
Market and Performance Based Vesting
Aggregate intrinsic value
Unrecognized compensation costs	$ 408
Performance and Time Based Vesting
Aggregate intrinsic value
Unrecognized compensation costs	$ 5,771

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted stock activity (Details) - Restricted stock	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Number of Shares
Beginning balance (in shares) | shares	252,307
Granted (in shares) | shares	359,691
Vested (in shares) | shares	(100,553)
Forfeited/Cancelled (in shares) | shares	(70,382)
Ending balance (in shares) | shares	441,063
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance (in USD per share) | $ / shares	$ 16.70
Granted (in USD per share) | $ / shares	22.18
Vested (in USD per share) | $ / shares	16.91
Forfeited/Cancelled (in USD per share) | $ / shares	19.48
Ending balance (in USD per share) | $ / shares	$ 20.68

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
RELATED PARTY TRANSACTIONS
Period of weighted average maturity, clinic loans	11 months
Weighted average interest rate, clinic loans	5.12%
Sublease agreement
RELATED PARTY TRANSACTIONS
Total amount of initial financing	$ 2,445
Interest rate	6.00%
Amount outstanding	$ 2,224
Executive | Financing Transactions
RELATED PARTY TRANSACTIONS
Principal loan outstanding amount on joint venture	$ 4,065	$ 6,027	$ 7,213
Period of weighted average maturity, clinic loans	3 years 4 months 12 days
Weighted average interest rate, clinic loans	4.80%
Loan guarantee	$ 692
Affiliated entity | Software services agreement
RELATED PARTY TRANSACTIONS
Expense related to agreement	$ 318	$ 310	$ 344
Minimum
RELATED PARTY TRANSACTIONS
Interest rate	4.25%
Minimum | Executive | Financing Transactions
RELATED PARTY TRANSACTIONS
Interest rate	3.31%
Maximum
RELATED PARTY TRANSACTIONS
Interest rate	8.08%
Maximum | Executive | Financing Transactions
RELATED PARTY TRANSACTIONS
Interest rate	6.30%
Kinetic | Executive | Software services agreement
RELATED PARTY TRANSACTIONS
Ownership percentage	51.00%
Kinetic | Spouse of executive | Software services agreement
RELATED PARTY TRANSACTIONS
Ownership percentage	2.50%

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Apr. 26, 2016
Commitments and Contingencies Disclosure [Abstract]
Obligations under contracts related to the construction of clinics		$ 4,367
Purchase obligations, term		5 years
Subsequent Event [Line Items]
Purchase obligations for minimum purchase commitments		$ 139,625
Percentage tax savings payable to pre-IPO stockholders			85.00%
Subsequent Event
Subsequent Event [Line Items]
Purchase obligations for minimum purchase commitments	$ 105,000

Certain Legal Matters and Oth_2

Certain Legal Matters and Other Matters (Details) $ in Thousands	Aug. 01, 2018USD ($)payment_installment	Jun. 15, 2018USD ($)	May 31, 2018USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)
Loss Contingencies [Line Items]
Classified as accrued expenses and other current liabilities				$ 61,116	$ 56,538	$ 62,950	$ 63,790	$ 64,575	$ 57,199	$ 70,695	$ 58,559	$ 63,022	$ 59,388	$ 56,818	$ 45,210
Classified in other long-term liabilities				24,813	$ 24,375	$ 33,816	$ 14,147	$ 14,880	$ 15,713	$ 13,856	$ 12,823	$ 11,670	$ 11,262	$ 10,355	$ 9,927
ARA, ARA OpCo and ARM v. UnitedHealth Group Inc.
Loss Contingencies [Line Items]
Legal settlement amount	$ 32,000
Number of payment installments for litigation settlement | payment_installment	5
Initial present value of settlement	$ 29,614			19,614
Classified as accrued expenses and other current liabilities				7,641
Classified in other long-term liabilities				11,973
First installment				10,000
Installment paid August 1, 2019				8,000
Installment to be paid August 1, 2020				7,000
Installment to be paid August 1, 2021				3,500
Installment to be paid August 1, 2022				$ 3,500
Term of agreement	3 years
Esposito, Et Al. v. American Renal Associates Holdings, Inc., Et Al
Loss Contingencies [Line Items]
Legal settlement amount		$ 4,000
Bushansky on Behalf of Company v. Board of Directors
Loss Contingencies [Line Items]
Legal settlement amount			$ 350

Employee Benefit Plan (Details)

Employee Benefit Plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Contributions made to plan	$ 0	$ 0	$ 0

Concentrations (Details)

Concentrations (Details)	Dec. 31, 2018USD ($)
Maximum
Federal Deposit Insurance Corporation (FDIC)	$ 250,000

Subsequent Events - Acquisition

Subsequent Events - Acquisitions (Details) - USD ($) $ in Thousands	8 Months Ended
	Sep. 04, 2019	Jan. 01, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill			$ 571,339	$ 571,339	$ 571,339	$ 571,341	$ 573,145	$ 572,420	$ 572,800	$ 573,092	$ 573,092	$ 573,052	$ 569,876	$ 569,261	$ 569,264
Goodwill expected to be deductible for tax purposes			$ 647								$ 3,723
Subsequent Event | Acquisitions 2019
Business Acquisition [Line Items]
Cash	$ 6,590
Equity interests	4,655
Fair value of total consideration transferred	11,245
Subsequent Event | Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Property and equipment	1,657
Noncompete agreements	660
Goodwill	8,683
Other assets	245
Cash consideration paid	$ 11,245
Subsequent Event | Acquisition of dialysis center in Florida
Business Acquisition [Line Items]
Goodwill expected to be deductible for tax purposes		$ 4,774

Subsequent Events - Narrative (

Subsequent Events - Narrative (Details) $ in Thousands

Jul. 01, 2019USD ($)dialysis_clinic

Mar. 25, 2019USD ($)

Mar. 01, 2019USD ($)dialysis_clinic

Sep. 30, 2019USD ($)

Jun. 30, 2019USD ($)

Mar. 31, 2019USD ($)

Mar. 31, 2018USD ($)

Jun. 30, 2017USD ($)

Jun. 30, 2016USD ($)

Mar. 31, 2016USD ($)

Jun. 30, 2018USD ($)

Jun. 30, 2017USD ($)

Jun. 30, 2016USD ($)

Sep. 30, 2018USD ($)

Sep. 30, 2017USD ($)

Sep. 30, 2016USD ($)

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Apr. 30, 2019USD ($)

Subsequent Event [Line Items]

Reduction of goodwill on sale of dialysis clinics

$ 1,806

$ 672

Current assets held for sale

577

0

$ 0

Professional fees

$ 856

$ 717

$ 2,215

$ 24

$ 856

$ 717

$ 2,239

$ 856

$ 717

$ 2,239

$ 856

$ 717

$ 2,239

Subsequent Event

Subsequent Event [Line Items]

Current assets held for sale

$ 14,061

Maximum | Subsequent Event

Subsequent Event [Line Items]

Maximum amount payable under retention plan

$ 2,005

Two Dialysis Clinics In Florida | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Subsequent Event

Subsequent Event [Line Items]

Ownership interest disposed

100.00%

Number of dialysis clinics disposed | dialysis_clinic

2

Proceeds from sale of dialysis clinics

$ 3,300

Gain on sale of dialysis clinics

$ 512

Reduction of goodwill on sale of dialysis clinics

$ 2,210

Two Dialysis Clinics In Maryland | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Subsequent Event

Subsequent Event [Line Items]

Ownership interest disposed

100.00%

Number of dialysis clinics disposed | dialysis_clinic

2

Proceeds from sale of dialysis clinics

$ 3,000

Independent Contractor Agreement, ECG Ventures, Inc. | Director | Subsequent Event

Subsequent Event [Line Items]

Professional fees

$ 100

Expense related to agreement

$ 656

Forecast | Two Dialysis Clinics In Maryland | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Subsequent Event

Subsequent Event [Line Items]

Gain on sale of dialysis clinics

$ 264

Reduction of goodwill on sale of dialysis clinics

$ 2,155

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended											6 Months Ended			9 Months Ended			12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Patient service operating revenues	$ 207,806	$ 205,719	$ 205,952	$ 186,299								$ 392,251			$ 597,970			$ 805,776
Patient service operating revenues					$ 190,509	$ 190,670	$ 177,890	$ 178,249	$ 195,103	$ 197,752	$ 184,834		$ 356,139	$ 382,586		$ 546,809	$ 577,689		$ 737,318	$ 772,221
Net patient service operating revenues					187,331	187,918	177,459	176,294	192,139	196,156	183,551		353,753	379,707		541,671	571,846		729,002	766,780
Operating Income (loss)	22,949	24,110	(4,310)	12,573	27,033	33,224	18,277	11,674	29,941	43,871	48,752	8,263	29,951	92,623	32,373	63,175	122,564	55,322	90,208	143,526
Income (loss) before income taxes	19,590	12,388	(10,710)	4,095	21,549	29,554	7,922	8,582
Net (loss) income attributable to American Renal Associates Holdings, Inc.	$ (572)	$ (734)	$ (23,659)	$ (3,802)	$ (4,898)	$ 7,496	$ (5,073)	$ (2,122)	$ 12,772	$ (7,073)	$ 6,521	$ (27,461)	$ (7,195)	$ (552)	$ (28,195)	$ 301	$ 12,220	$ (28,767)	$ (4,597)	$ 3,146
Basic (loss) income per share attributable to American Renal Associates Holdings, Inc. (in USD per share)	$ (0.06)	$ (0.04)	$ (0.78)	$ (0.10)	$ (0.12)	$ 0.26	$ (0.26)	$ (0.41)	$ 0.31	$ (0.61)	$ 0.29	$ (0.89)	$ (0.66)	$ (0.43)	$ (0.93)	$ (0.40)	$ (0.05)	$ (0.98)	$ (0.52)	$ (0.25)
Diluted (loss) income per share attributable to American Renal Associates Holdings, Inc. (in USD per share)	$ (0.06)	$ (0.04)	$ (0.78)	$ (0.10)	$ (0.12)	$ 0.24	$ (0.26)	$ (0.41)	$ 0.30	$ (0.61)	$ 0.29	$ (0.89)	$ (0.66)	$ (0.43)	$ (0.93)	$ (0.40)	$ (0.05)	$ (0.98)	$ (0.52)	$ (0.25)

Selected Quarterly Financial _4

Selected Quarterly Financial Data (Unaudited) - Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Assets
Cash	$ 55,200	$ 61,862	$ 69,393	$ 64,273	$ 71,511	$ 67,583	$ 74,922	$ 83,993	$ 100,905	$ 105,138	$ 93,262	$ 95,961
Accounts receivable, net of allowance for doubtful accounts	99,526	98,678	104,890	110,331	112,642	121,260	117,660	125,849	130,211	130,518	130,985	119,323
Inventories	11,433	6,382	6,535	6,129	4,665	4,672	4,960	4,648	4,676	4,468	4,790	5,515
Prepaid expenses and other current assets	28,127	18,716	19,087	25,277	24,998	17,133	23,150	18,217	18,498	12,914	14,902	19,395
Income tax receivable		0	0	0	0	0	0	0	0	0	0	0
Total current assets	194,863	185,638	199,905	206,010	213,816	210,648	220,692	232,707	254,290	253,038	243,939	240,194
Property and equipment, net of accumulated depreciation	180,268	168,346	167,621	168,682	168,537	166,890	165,495	167,338	170,118	165,132	160,887	151,204
Deferred tax assets	0	4,596	4,596		0	9,635	9,635	9,691	10,349
Intangible assets, net of accumulated amortization	24,628	24,811	24,966	25,182	25,368	25,488	25,638	25,681	25,626	25,943	25,938	25,877
Other long-term assets	14,745	18,198	19,639	15,013	9,285	8,636	8,885	7,472	6,753	6,593	6,174	6,574
Goodwill	571,339	571,339	571,339	571,341	573,145	572,420	572,800	573,092	573,092	573,052	569,876	569,261	$ 569,264
Total assets	985,843	972,928	988,066	986,228	990,151	993,717	1,003,145	1,015,981	1,040,228	1,023,758	1,006,814	993,110
Liabilities and Equity
Accounts payable	59,082	54,023	52,849	40,885	33,421	33,863	28,184	24,605	31,127	23,277	23,515	23,857
Accrued compensation and benefits	34,587	34,658	30,881	27,160	28,985	31,767	28,654	26,092	29,103	29,092	25,469	21,496
Accrued expenses and other current liabilities	61,116	56,538	62,950	63,790	64,575	57,199	70,695	58,559	63,022	59,388	56,818	45,210
Current portion of long-term debt	42,855	47,206	46,660	45,121	44,534	44,189	45,711	45,559	48,274	43,582	40,579	27,171
Total current liabilities	197,640	192,425	193,340	176,956	171,515	167,018	173,244	154,815	171,526	155,339	146,381	117,734
Long-term debt, less current portion	517,511	506,750	509,983	512,822	515,554	514,846	516,442	520,364	522,058	520,017	517,798	661,369
Income tax receivable agreement payable	3,700	9,476	6,037	8,646	7,500	11,900	15,600	16,683	21,200	15,670	27,800
Other long-term liabilities	24,813	24,375	33,816	14,147	14,880	15,713	13,856	12,823	11,670	11,262	10,355	9,927
Deferred tax liabilities	3,169	0	0	422	422	0	0	0	0	7,954	7,954	7,954
Total liabilities	746,833	733,026	743,176	712,993	709,871	709,477	719,142	704,685	726,454	710,242	710,288	796,984
Commitments and contingencies
Noncontrolling interests subject to put provisions	129,099	141,236	140,737	139,791	130,438	133,716	132,494	158,086	150,049	151,916	151,624	124,972
Equity:
Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued	0	0	0	0	0	0	0	0	0	0	0	0
Common stock	196	195	195	195	193	186	185	184	184	184	184	98
Additional paid-in capital	105,715	93,217	93,339	98,243	99,098	95,359	101,375	93,960	100,687	84,165	81,849	6,853
Receivable from noncontrolling interests	(506)	(1,340)	(477)	(515)	(358)	(484)	(415)	(747)	(544)	(562)	(498)	(605)
Accumulated deficit	(164,451)	(163,878)	(163,145)	(139,486)	(135,898)	(131,200)	(138,588)	(133,423)	(131,301)	(122,226)	(134,999)	(127,940)
Accumulated other comprehensive income (loss), net of tax	76	1,440	1,013	546	(891)	(1,447)	(1,420)	(744)	(100)	(201)	(301)	(401)
Total American Renal Associates Holdings, Inc. deficit	(58,970)	(70,366)	(69,075)	(41,017)	(37,856)	(37,586)	(38,863)	(40,770)	(31,074)	(38,640)	(53,765)	(121,995)	$ (123,211)
Noncontrolling interests not subject to put provisions	168,881	169,032	173,228	174,461	187,698	188,110	190,372	193,980	194,799	200,240	198,667	193,149
Total equity	109,911	98,666	104,153	133,444	149,842	150,524	151,509	153,210	163,725	161,600	144,902	71,154
Total liabilities and equity	$ 985,843	972,928	988,066	986,228	990,151	993,717	1,003,145	1,015,981	1,040,228	1,023,758	1,006,814	993,110
As Reported
Assets
Cash		61,872	69,403	64,283	71,521	67,593	74,933	84,003	100,916	105,149	93,268	95,965
Accounts receivable, net of allowance for doubtful accounts		90,596	91,508	85,723	79,662	81,234	77,841	77,495	81,127	77,253	76,904	75,831
Inventories		6,382	6,535	7,642	4,665	4,672	4,960	4,648	4,676	4,468	4,790	5,515
Prepaid expenses and other current assets		20,608	20,338	24,478	24,998	17,133	23,150	18,217	18,498	12,951	14,977	19,507
Income tax receivable		5,306	4,713	7,835	6,745	8,071	10,254	9,415	5,163	4,656	144	2,661
Total current assets		184,764	192,497	189,961	187,591	178,703	191,138	193,778	210,380	204,477	190,083	199,479
Property and equipment, net of accumulated depreciation		168,346	167,621	168,682	168,537	166,890	165,495	167,338	170,118	165,132	160,887	151,204
Deferred tax assets		0	0			0	0	0	0
Intangible assets, net of accumulated amortization		24,811	24,966	25,182	25,368	25,488	25,638	25,681	25,626	25,943	25,938	25,877
Other long-term assets		18,198	19,639	15,013	9,285	8,636	8,885	7,472	6,753	6,593	6,174	6,574
Goodwill		570,944	570,946	570,946	573,427	572,702	573,147	573,147	573,147	573,107	569,930	569,315
Total assets		967,063	975,669	969,784	964,208	952,419	964,303	967,416	986,024	975,252	953,012	952,449
Liabilities and Equity
Accounts payable		54,023	52,849	40,885	33,421	33,863	28,184	24,605	31,127	23,277	23,515	23,857
Accrued compensation and benefits		34,658	30,881	27,160	28,985	31,767	28,654	26,092	29,103	29,092	25,469	21,496
Accrued expenses and other current liabilities		43,153	48,961	51,954	49,963	43,797	60,663	45,075	45,286	54,031	45,642	31,110
Current portion of long-term debt		47,206	46,660	45,121	44,534	44,189	45,711	45,559	48,274	43,582	40,579	27,171
Total current liabilities		179,040	179,351	165,120	156,903	153,616	163,212	141,331	153,790	149,982	135,205	103,634
Long-term debt, less current portion		506,750	509,983	512,822	515,554	514,846	516,442	520,364	522,058	520,017	517,798	661,369
Income tax receivable agreement payable		9,476	6,037	8,646	7,500	11,900	15,600	16,683	21,200	15,670	27,800
Other long-term liabilities		24,378	33,819	14,171	14,880	15,713	13,859	12,826	11,670	11,262	10,361	9,927
Deferred tax liabilities		4,843	4,696	9,560	8,991	1,110	1,128	1,522	1,278	6,722	7,169	15,096
Total liabilities		724,487	733,886	710,319	703,828	697,185	710,241	692,726	709,996	703,653	698,333	790,026
Commitments and contingencies
Noncontrolling interests subject to put provisions		150,152	145,500	148,769	139,895	110,988	113,925	132,465	130,365	140,336	134,762	107,414
Equity:
Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued		0	0	0	0	0	0	0	0	0	0	0
Common stock		195	195	195	193	186	185	184	184	184	184	98
Additional paid-in capital		65,965	69,170	68,632	67,853	94,158	95,369	93,596	95,062	69,765	72,405	457
Receivable from noncontrolling interests		(1,340)	(477)	(515)	(358)	(484)	(415)	(747)	(544)	(562)	(498)	(605)
Accumulated deficit		(140,003)	(142,493)	(124,485)	(123,789)	(124,020)	(132,003)	(129,897)	(128,646)	(121,527)	(133,597)	(124,505)
Accumulated other comprehensive income (loss), net of tax		1,654	1,227	760	(677)	(1,447)	(1,420)	(744)	(100)	(201)	(301)	(401)
Total American Renal Associates Holdings, Inc. deficit		(73,529)	(72,378)	(55,413)	(56,778)	(31,607)	(38,284)	(37,608)	(34,044)	(52,341)	(61,807)	(124,956)
Noncontrolling interests not subject to put provisions		165,953	168,661	166,109	177,263	175,853	178,421	179,833	179,707	183,604	181,724	179,965
Total equity		92,424	96,283	110,696	120,485	144,246	140,137	142,225	145,663	131,263	119,917	55,009
Total liabilities and equity		967,063	975,669	969,784	964,208	952,419	964,303	967,416	986,024	975,252	953,012	952,449
Restatement Adjustments
Assets
Cash		(10)	(10)	(10)	(10)	(10)	(11)	(10)	(11)	(11)	(6)	(4)
Accounts receivable, net of allowance for doubtful accounts		8,082	13,382	24,608	32,980	40,026	39,819	48,354	49,084	53,265	54,081	43,492
Inventories		0	0	(1,513)	0	0	0	0	0	0	0	0
Prepaid expenses and other current assets		(1,892)	(1,251)	799	0	0	0	0	0	(37)	(75)	(112)
Income tax receivable		(5,306)	(4,713)	(7,835)	(6,745)	(8,071)	(10,254)	(9,415)	(5,163)	(4,656)	(144)	(2,661)
Total current assets		874	7,408	16,049	26,225	31,945	29,554	38,929	43,910	48,561	53,856	40,715
Property and equipment, net of accumulated depreciation		0	0	0	0	0	0	0	0	0	0	0
Deferred tax assets		4,596	4,596			9,635	9,635	9,691	10,349
Intangible assets, net of accumulated amortization		0	0	0	0	0	0	0	0	0	0	0
Other long-term assets		0	0	0	0	0	0	0	0	0	0	0
Goodwill		395	393	395	(282)	(282)	(347)	(55)	(55)	(55)	(54)	(54)
Total assets		5,865	12,397	16,444	25,943	41,298	38,842	48,565	54,204	48,506	53,802	40,661
Liabilities and Equity
Accounts payable		0	0	0	0	0	0	0	0	0	0	0
Accrued compensation and benefits		0	0	0	0	0	0	0	0	0	0	0
Accrued expenses and other current liabilities		13,385	13,989	11,836	14,612	13,402	10,032	13,484	17,736	5,357	11,176	14,100
Current portion of long-term debt		0	0	0	0	0	0	0	0	0	0	0
Total current liabilities		13,385	13,989	11,836	14,612	13,402	10,032	13,484	17,736	5,357	11,176	14,100
Long-term debt, less current portion		0	0	0	0	0	0	0	0	0	0	0
Income tax receivable agreement payable		0	0	0	0	0	0	0	0	0	0
Other long-term liabilities		(3)	(3)	(24)	0	0	(3)	(3)	0	0	(6)	0
Deferred tax liabilities		(4,843)	(4,696)	(9,138)	(8,569)	(1,110)	(1,128)	(1,522)	(1,278)	1,232	785	(7,142)
Total liabilities		8,539	9,290	2,674	6,043	12,292	8,901	11,959	16,458	6,589	11,955	6,958
Commitments and contingencies
Noncontrolling interests subject to put provisions		(8,916)	(4,763)	(8,978)	(9,457)	22,728	18,569	25,621	19,684	11,580	16,862	17,558
Equity:
Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued		0	0	0	0	0	0	0	0	0	0	0
Common stock		0	0	0	0	0	0	0	0	0	0	0
Additional paid-in capital		27,252	24,169	29,611	31,245	1,201	6,006	364	5,625	14,400	9,444	6,396
Receivable from noncontrolling interests		0	0	0	0	0	0	0	0	0	0	0
Accumulated deficit		(23,875)	(20,652)	(15,001)	(12,109)	(7,180)	(6,585)	(3,526)	(2,655)	(699)	(1,402)	(3,435)
Accumulated other comprehensive income (loss), net of tax		(214)	(214)	(214)	(214)	0	0	0	0	0	0	0
Total American Renal Associates Holdings, Inc. deficit		3,163	3,303	14,396	18,922	(5,979)	(579)	(3,162)	2,970	13,701	8,042	2,961
Noncontrolling interests not subject to put provisions		3,079	4,567	8,352	10,435	12,257	11,951	14,147	15,092	16,636	16,943	13,184
Total equity		6,242	7,870	22,748	29,357	6,278	11,372	10,985	18,062	30,337	24,985	16,145
Total liabilities and equity		$ 5,865	$ 12,397	$ 16,444	$ 25,943	$ 41,298	$ 38,842	$ 48,565	$ 54,204	$ 48,506	$ 53,802	$ 40,661

Selected Quarterly Financial _5

Selected Quarterly Financial Data (Unaudited) - Condensed Consolidated Balance Sheets (Parenthetical) (Details) - $ / shares	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Apr. 07, 2016	Mar. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Preferred stock, par value (in USD per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01		$ 0.01
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000	1,000,000		1,000,000
Preferred stock, issued (in shares)	0	0	0	0	0	0	0	0	0	0	0		0
Common stock, par value (in USD per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000	300,000,000
Common stock, shares issued (in shares)	32,603,846	32,514,777	32,458,837	32,437,507	32,034,439	31,314,217	31,283,812	31,142,998	30,894,962	30,868,050	30,845,109		29,770,000
Common stock, shares outstanding (in shares)	32,603,846	32,514,777	32,458,837	32,437,507	32,034,439	31,314,217	31,283,812	31,142,998	30,894,962	30,868,050	30,845,109		29,770,000

Selected Quarterly Financial _6

Selected Quarterly Financial Data (Unaudited) - Condensed Consolidated Statements of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended											6 Months Ended			9 Months Ended			12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Patient service operating revenues	$ 207,806	$ 205,719	$ 205,952	$ 186,299								$ 392,251			$ 597,970			$ 805,776
Patient service operating revenues					$ 190,509	$ 190,670	$ 177,890	$ 178,249	$ 195,103	$ 197,752	$ 184,834		$ 356,139	$ 382,586		$ 546,809	$ 577,689		$ 737,318	$ 772,221
Provision for uncollectible accounts						(2,752)	(431)	(1,955)	(2,964)	(1,596)	(1,283)		(2,386)	(2,879)		(5,138)	(5,843)		(8,316)	(5,441)
Net patient service operating revenues					187,331	187,918	177,459	176,294	192,139	196,156	183,551		353,753	379,707		541,671	571,846		729,002	766,780
Operating expenses:
Patient care costs		145,939	141,468	134,077		119,739	118,568	120,301	116,115	109,779	105,455	275,545	238,869	215,234	421,484	358,608	331,349	570,009	483,101	452,453
General and administrative		24,619	26,434	25,067		22,036	26,218	31,309	33,354	32,039	21,643	51,501	57,527	53,682	76,120	79,563	87,036	101,101	102,093	127,921
Transaction-related costs				856			717			2,215	24	856	717	2,239	856	717	2,239	856	717	2,239
Depreciation and amortization		10,023	9,814	9,623		9,438	9,382	9,074	8,687	8,252	7,677	19,437	18,456	15,929	29,460	27,894	24,616	39,802	37,634	33,862
Certain legal and other matters		1,028	32,546	4,103		3,481	4,297	3,936	4,042			36,649	8,233		37,677	11,714	4,042		15,249	6,779
Total operating expenses		181,609	210,262	173,726		154,694	159,182	164,620	162,198	152,285	134,799	383,988	323,802	287,084	565,597	478,496	449,282	750,454	638,794	623,254
Operating income	22,949	24,110	(4,310)	12,573	27,033	33,224	18,277	11,674	29,941	43,871	48,752	8,263	29,951	92,623	32,373	63,175	122,564	55,322	90,208	143,526
Interest expense, net		(8,242)	(8,136)	(7,457)		(7,255)	(7,188)	(7,609)	(7,372)	(8,951)	(12,263)	(15,593)	(14,797)	(21,214)	(23,835)	(22,052)	(28,586)	(32,632)	(29,309)	(35,959)
Loss on early extinguishment of debt							(526)			(4,708)			(526)	(4,708)		(526)	(4,708)	0	(526)	(4,708)
Change in fair value of income tax receivable agreement		(3,480)	1,736	(1,021)		3,585	(2,641)	4,517	12,565	(7,835)		715	1,876	(7,835)	(2,765)	5,461	4,730	2,673	7,234	1,286
Income before income taxes		12,388	(10,710)	4,095		29,554	7,922	8,582	35,134	22,377	36,489	(6,615)	16,504	58,866	5,773	46,058	94,000	25,363	67,607	104,145
Income tax (benefit) expense		(124)	(2,327)	(3,069)		3,763	(1,837)	(3,180)	(983)	1,208	4,499	(5,396)	(5,017)	5,707	(5,520)	(1,254)	4,724	2,896	9,471	2,479
Net income (loss)		12,512	(8,383)	7,164		25,791	9,759	11,762	36,117	21,169	31,990	(1,219)	21,521	53,159	11,293	47,312	89,276	22,467	58,136	101,666
Less: Net income attributable to noncontrolling interests		(13,246)	(15,276)	(10,966)		(18,295)	(14,832)	(13,884)	(23,345)	(28,242)	(25,469)	(26,242)	(28,716)	(53,711)	(39,488)	(47,011)	(77,056)	(51,234)	(62,733)	(98,520)
Net (loss) income attributable to American Renal Associates Holdings, Inc.	$ (572)	(734)	(23,659)	(3,802)	$ (4,898)	7,496	(5,073)	(2,122)	12,772	(7,073)	6,521	(27,461)	(7,195)	(552)	(28,195)	301	12,220	(28,767)	(4,597)	3,146
Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests		(580)	(1,248)	497		559	(2,884)	(10,407)	(3,339)	(10,322)	0	(751)	(13,291)	(10,322)	(1,331)	(12,732)	(13,661)	(2,566)	(11,503)	(10,067)
Net income (loss) attributable to common shareholders		$ (1,314)	$ (24,907)	$ (3,305)		$ 8,055	$ (7,957)	$ (12,529)	$ 9,433	$ (17,395)	$ 6,521	$ (28,212)	$ (20,486)	$ (10,874)	$ (29,526)	$ (12,431)	$ (1,441)	$ (31,333)	$ (16,100)	$ (6,921)
Earnings (loss) per share:
Basic (in USD per share)	$ (0.06)	$ (0.04)	$ (0.78)	$ (0.10)	$ (0.12)	$ 0.26	$ (0.26)	$ (0.41)	$ 0.31	$ (0.61)	$ 0.29	$ (0.89)	$ (0.66)	$ (0.43)	$ (0.93)	$ (0.40)	$ (0.05)	$ (0.98)	$ (0.52)	$ (0.25)
Diluted (in USD per share)	$ (0.06)	$ (0.04)	$ (0.78)	$ (0.10)	$ (0.12)	$ 0.24	$ (0.26)	$ (0.41)	$ 0.30	$ (0.61)	$ 0.29	$ (0.89)	$ (0.66)	$ (0.43)	$ (0.93)	$ (0.40)	$ (0.05)	$ (0.98)	$ (0.52)	$ (0.25)
Weighted-average number of common shares outstanding
Basic (in shares)		32,005,544	31,932,705	31,800,553		31,095,418	30,986,689	30,907,482	30,865,350	28,406,999	22,213,967	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297	31,965,844	31,081,824	28,118,673
Diluted (in shares)		32,005,544	31,932,705	31,800,553		33,833,822	30,986,689	30,907,482	31,436,814	28,406,999	22,785,670	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297	31,965,844	31,081,824	28,118,673
Cash dividends declared per share (in USD per share)										$ 1.30				$ 1.3			$ 1.30	$ 0	$ 0	$ 1.30
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Patient service operating revenues		$ 211,019	$ 217,178	$ 194,672								$ 411,850			$ 622,869
Patient service operating revenues						$ 189,497	$ 187,602	$ 178,632	$ 194,857	$ 186,938	$ 173,554		$ 366,234	$ 360,492		$ 555,731	$ 555,349		$ 752,510	$ 756,329
Provision for uncollectible accounts						(1,786)	(1,610)	(1,607)	(1,902)	(1,371)	(1,423)		(3,217)	(2,794)		(5,003)	(4,696)		(7,404)	(6,562)
Net patient service operating revenues						187,711	185,992	177,025	192,955	185,567	172,131		363,017	357,698		550,728	550,653		745,106	749,767
Operating expenses:
Patient care costs		145,300	140,562	133,731		119,599	118,059	120,301	116,115	109,779	105,455	274,293	238,360	215,234	419,593	357,959	331,349		482,450	452,449
General and administrative		24,619	26,803	24,960		22,292	26,381	31,244	33,359	31,942	21,499	51,763	57,625	53,441	76,382	79,917	86,800		102,598	127,631
Transaction-related costs				856			717			2,215	24	856	717	2,239	856	717	2,239		717	2,239
Depreciation and amortization		10,023	9,814	9,623		9,438	9,382	9,074	8,687	8,252	7,677	19,437	18,456	15,929	29,460	27,894	24,616		37,634	33,862
Certain legal and other matters		1,028	32,546	4,103		3,481	4,297	3,936	4,042			36,649	8,233		37,677	11,714	4,042		15,249	6,779
Total operating expenses		180,970	209,725	173,273		154,810	158,836	164,555	162,203	152,188	134,655	382,998	323,391	286,843	563,968	478,201	449,046		638,648	622,960
Operating income		30,049	7,453	21,399		32,901	27,156	12,470	30,752	33,379	37,476	28,852	39,626	70,855	58,901	72,527	101,607		106,458	126,807
Interest expense, net		(8,241)	(8,131)	(7,457)		(7,255)	(7,188)	(7,609)	(7,372)	(8,941)	(12,258)	(15,588)	(14,797)	(21,199)	(23,829)	(22,052)	(28,571)		(29,289)	(35,933)
Loss on early extinguishment of debt							(526)			(4,708)			(526)	(4,708)		(526)	(4,708)		(526)	(4,708)
Change in fair value of income tax receivable agreement		(3,480)	1,736	(1,021)		3,585	(2,641)	4,517	12,565	(7,835)		715	1,876	(7,835)	(2,765)	5,461	4,730		7,234	1,286
Income before income taxes		18,328	1,058	12,921		29,231	16,801	9,378	35,945	11,895	25,218	13,979	26,179	37,113	32,307	55,410	73,058		83,877	87,452
Income tax (benefit) expense		34	(1,219)	(792)		2,559	410	(3,524)	(101)	(1,147)	2,661	(2,011)	(3,114)	1,514	(1,977)	(555)	1,413		8,194	(753)
Net income (loss)		18,294	2,277	13,713		26,672	16,391	12,902	36,046	13,042	22,557	15,990	29,293	35,599	34,284	55,965	71,645		75,683	88,205
Less: Net income attributable to noncontrolling interests		(15,804)	(20,285)	(14,623)		(18,689)	(18,497)	(14,153)	(23,622)	(22,488)	(18,801)	(34,908)	(32,650)	(41,289)	(50,712)	(51,339)	(64,911)		(70,826)	(88,590)
Net (loss) income attributable to American Renal Associates Holdings, Inc.		2,490	(18,008)	(910)		7,983	(2,106)	(1,251)	12,424	(9,446)	3,756	(18,918)	(3,357)	(5,690)	(16,428)	4,626	6,734		4,857	(385)
Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests		(481)	(884)	582		5	(2,527)	(11,083)	(1,752)	(12,133)	0	(302)	(13,610)	(12,133)	(783)	(13,605)	(13,885)		(12,276)	(7,404)
Net income (loss) attributable to common shareholders		$ 2,009	$ (18,892)	$ (328)		$ 7,988	$ (4,633)	$ (12,334)	$ 10,672	$ (21,579)	$ 3,756	$ (19,220)	$ (16,967)	$ (17,823)	$ (17,211)	$ (8,979)	$ (7,151)		$ (7,419)	$ (7,789)
Earnings (loss) per share:
Basic (in USD per share)		$ 0.06	$ (0.59)	$ (0.01)		$ 0.26	$ (0.15)	$ (0.40)	$ 0.35	$ (0.76)	$ 0.17	$ (0.60)	$ (0.55)	$ (0.70)	$ (0.54)	$ (0.29)	$ (0.26)		$ (0.24)	$ (0.28)
Diluted (in USD per share)		$ 0.06	$ (0.59)	$ (0.01)		$ 0.24	$ (0.15)	$ (0.40)	$ 0.34	$ (0.76)	$ 0.16	$ (0.60)	$ (0.55)	$ (0.70)	$ (0.54)	$ (0.29)	$ (0.26)		$ (0.24)	$ (0.28)
Weighted-average number of common shares outstanding
Basic (in shares)		32,005,544	31,932,705	31,800,553		31,095,418	30,986,689	30,907,482	30,865,350	28,406,999	22,213,967	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297		31,081,824	28,116,673
Diluted (in shares)		34,578,592	31,932,705	31,800,553		33,833,822	30,986,689	30,907,482	31,436,814	28,406,999	22,785,670	31,877,286	30,947,304	25,344,510	31,912,934	30,997,218	27,198,297		31,081,824	28,116,673
Cash dividends declared per share (in USD per share)										$ 1.30				$ 1.3			$ 1.30			$ 1.30
Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Patient service operating revenues		$ (5,300)	$ (11,226)	$ (8,373)								$ (19,599)			$ (24,899)
Patient service operating revenues						$ 1,173	$ (9,712)	$ (383)	$ 246	$ 10,814	$ 11,280		$ (10,095)	$ 22,094		$ (8,922)	$ 22,340		$ (15,192)	$ 15,892
Provision for uncollectible accounts						(966)	1,179	(348)	(1,062)	(225)	140		831	(85)		(135)	(1,147)		(912)	1,121
Net patient service operating revenues						207	(8,533)	(731)	(816)	10,589	11,420		(9,264)	22,009		(9,057)	21,193		(16,104)	17,013
Operating expenses:
Patient care costs		639	906	346		140	509	0	0	0	0	1,252	509	0	1,891	649	0		651	4
General and administrative		0	(369)	107		(256)	(163)	65	(5)	97	144	(262)	(98)	241	(262)	(354)	236		(505)	290
Transaction-related costs				0			0			0	0	0	0	0	0	0	0		0	0
Depreciation and amortization		0	0	0		0	0	0	0	0	0	0	0	0	0	0	0		0	0
Certain legal and other matters		0	0	0		0	0	0	0			0	0		0	0	0		0	0
Total operating expenses		639	537	453		(116)	346	65	(5)	97	144	990	411	241	1,629	295	236		146	294
Operating income		(5,939)	(11,763)	(8,826)		323	(8,879)	(796)	(811)	10,492	11,276	(20,589)	(9,675)	21,768	(26,528)	(9,352)	20,957		(16,250)	16,719
Interest expense, net		(1)	(5)	0		0	0	0	0	(10)	(5)	(5)	0	(15)	(6)	0	(15)		(20)	(26)
Loss on early extinguishment of debt							0			0			0	0		0	0		0	0
Change in fair value of income tax receivable agreement		0	0	0		0	0	0	0	0		0	0	0	0	0	0		0	0
Income before income taxes		(5,940)	(11,768)	(8,826)		323	(8,879)	(796)	(811)	10,482	11,271	(20,594)	(9,675)	21,753	(26,534)	(9,352)	20,942		(16,270)	16,693
Income tax (benefit) expense		(158)	(1,108)	(2,277)		1,204	(2,247)	344	(882)	2,355	1,838	(3,385)	(1,903)	4,193	(3,543)	(699)	3,311		1,277	3,232
Net income (loss)		(5,782)	(10,660)	(6,549)		(881)	(6,632)	(1,140)	71	8,127	9,433	(17,209)	(7,772)	17,560	(22,991)	(8,653)	17,631		(17,547)	13,461
Less: Net income attributable to noncontrolling interests		2,558	5,009	3,657		394	3,665	269	277	(5,754)	(6,668)	8,666	3,934	(12,422)	11,224	4,328	(12,145)		8,093	(9,930)
Net (loss) income attributable to American Renal Associates Holdings, Inc.		(3,224)	(5,651)	(2,892)		(487)	(2,967)	(871)	348	2,373	2,765	(8,543)	(3,838)	5,138	(11,767)	(4,325)	5,486		(9,454)	3,531
Less: Change in the difference between the redemption value and estimated fair value for accounting purposes of the related noncontrolling interests		(99)	(364)	(85)		554	(357)	676	(1,587)	1,811	0	(449)	319	1,811	(548)	873	224		773	(2,663)
Net income (loss) attributable to common shareholders		$ (3,323)	$ (6,015)	$ (2,977)		$ 67	$ (3,324)	$ (195)	$ (1,239)	$ 4,184	$ 2,765	$ (8,992)	$ (3,519)	$ 6,949	$ (12,315)	$ (3,452)	$ 5,710		$ (8,681)	$ 868

Selected Quarterly Financial _7

Selected Quarterly Financial Data (Unaudited) - Consolidated Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended									6 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	$ 12,512	$ (8,383)	$ 7,164	$ 25,791	$ 9,759	$ 11,762	$ 36,117	$ 21,169	$ 31,990	$ (1,219)	$ 21,521	$ 53,159	$ 11,293	$ 47,312	$ 89,276	$ 22,467	$ 58,136	$ 101,666
Unrealized gain (loss) on derivative agreements, net of tax	427	467	1,651	(27)	(676)	(644)	100	100	100	2,118	(1,320)	200	2,545	(1,347)	300	1,181	(791)	401
Total comprehensive income	12,939	(7,916)	8,815	25,764	9,083	11,118	36,217	21,269	32,090	899	20,201	53,359	13,838	45,965	89,576	23,648	57,345	102,067
Less: Comprehensive income attributable to noncontrolling interests	(13,246)	(15,276)	(10,966)	(18,295)	(14,832)	(13,884)	(23,345)	(28,242)	(25,469)	(26,242)	(28,716)	(53,711)	(39,488)	(47,011)	(77,056)	(51,234)	(62,733)	(98,520)
Total comprehensive (loss) income attributable to American Renal Associates Holdings, Inc.	(307)	(23,192)	(2,151)	7,469	(5,749)	(2,766)	12,872	(6,973)	6,621	(25,343)	(8,515)	(352)	(25,650)	(1,046)	12,520	$ (27,586)	(5,388)	3,547
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	18,294	2,277	13,713	26,672	16,391	12,902	36,046	13,042	22,557	15,990	29,293	35,599	34,284	55,965	71,645		75,683	88,205
Unrealized gain (loss) on derivative agreements, net of tax	427	467	1,651	(27)	(676)	(644)	100	100	100	2,118	(1,320)	200	2,545	(1,347)	300		(577)	401
Total comprehensive income	18,721	2,744	15,364	26,645	15,715	12,258	36,146	13,142	22,657	18,108	27,973	35,799	36,829	54,618	71,945		75,106	88,606
Less: Comprehensive income attributable to noncontrolling interests	(15,804)	(20,285)	(14,623)	(18,689)	(18,497)	(14,153)	(23,622)	(22,488)	(18,801)	(34,908)	(32,650)	(41,289)	(50,712)	(51,339)	(64,911)		(70,826)	(88,590)
Total comprehensive (loss) income attributable to American Renal Associates Holdings, Inc.	2,917	(17,541)	741	7,956	(2,782)	(1,895)	12,524	(9,346)	3,856	(16,800)	(4,677)	(5,490)	(13,883)	3,279	7,034		4,280	16
Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	(5,782)	(10,660)	(6,549)	(881)	(6,632)	(1,140)	71	8,127	9,433	(17,209)	(7,772)	17,560	(22,991)	(8,653)	17,631		(17,547)	13,461
Unrealized gain (loss) on derivative agreements, net of tax	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0		(214)	0
Total comprehensive income	(5,782)	(10,660)	(6,549)	(881)	(6,632)	(1,140)	71	8,127	9,433	(17,209)	(7,772)	17,560	(22,991)	(8,653)	17,631		(17,761)	13,461
Less: Comprehensive income attributable to noncontrolling interests	2,558	5,009	3,657	394	3,665	269	277	(5,754)	(6,668)	8,666	3,934	(12,422)	11,224	4,328	(12,145)		8,093	(9,930)
Total comprehensive (loss) income attributable to American Renal Associates Holdings, Inc.	$ (3,224)	$ (5,651)	$ (2,892)	$ (487)	$ (2,967)	$ (871)	$ 348	$ 2,373	$ 2,765	$ (8,543)	$ (3,838)	$ 5,138	$ (11,767)	$ (4,325)	$ 5,486		$ (9,668)	$ 3,531

Selected Quarterly Financial _8

Selected Quarterly Financial Data (Unaudited) - Condensed Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended									6 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income	$ 12,512	$ (8,383)	$ 7,164	$ 25,791	$ 9,759	$ 11,762	$ 36,117	$ 21,169	$ 31,990	$ (1,219)	$ 21,521	$ 53,159	$ 11,293	$ 47,312	$ 89,276	$ 22,467	$ 58,136	$ 101,666
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization			9,623			9,074			7,677	19,437	18,456	15,929	29,460	27,894	24,616	39,802	37,634	33,862
Amortization of discounts, fees and deferred financing costs			497			530			797	989	1,065	1,807	1,384	1,534	2,432	1,981	2,031	2,595
Loss on early extinguishment of debt					526			4,708			526	4,708		526	4,708	0	526	4,708
Stock-based compensation			1,264			10,088			386	2,927	13,731	10,565	4,174	14,762	23,238	5,721	15,872	40,285
Premium paid for interest rate cap agreements						(1,186)					(1,186)			(1,186)		0	(1,186)	0
Deferred taxes			(569)			673			0	(5,737)	1,592	91	(5,884)	1,611	(201)	2,350	11,299	(18,570)
Change in fair value of income tax receivable agreement	3,480	(1,736)	1,021	(3,585)	2,641	(4,517)	(12,565)	7,835		(715)	(1,876)	7,835	2,765	(5,461)	(4,730)	(2,673)	(7,234)	(1,286)
Non-cash charge related to derivative agreements			1			173			623	5	173	850	18	173	489	46	173	473
Non-cash rent charges			167			289			512	161	431	920	400	588	1,764	73	1,044	2,191
Loss (gain) on disposal of assets			12			57				18	(60)		(81)	(315)		80	(27)	857
Change in operating assets and liabilities, net of acquisitions:
Accounts receivable			2,313			4,363			(10,332)	7,753	12,551	(21,995)	13,965	8,951	(21,527)	13,118	17,568	(21,221)
Inventories			(1,464)			28			(1,224)	(1,870)	(284)	(499)	(1,716)	4	(177)	(6,799)	11	(385)
Prepaid expenses and other current assets			(166)			798			(65)	6,338	(4,546)	(1,237)	7,261	1,484	836	(2,340)	(6,353)	(4,768)
Other assets			(4,313)			(63)			(18)	(8,733)	(552)	692	(7,291)	(558)	44	(5,712)	(1,325)	(219)
Accounts payable			7,464			(6,522)			1,286	19,428	(2,943)	944	20,602	2,736	706	25,661	2,294	8,556
Accrued compensation and benefits			(1,825)			(3,011)			(1,008)	1,896	(449)	2,965	5,673	2,664	6,588	5,602	(118)	6,599
Accrued expenses and other liabilities			(156)			(6,013)			5,954	17,837	(6,340)	12,495	1,686	(5,346)	13,836	7,027	(1,797)	16,863
Cash provided by operating activities			21,009			16,523			36,578	58,479	51,810	89,229	83,871	97,373	141,898	106,404	128,548	172,206
Investing activities
Purchases of property, equipment and intangible assets			(9,851)			(6,406)			(16,396)	(18,418)	(14,053)	(34,221)	(29,074)	(24,780)	(46,659)	(44,960)	(36,073)	(61,432)
Proceeds from asset sales			2,500							2,500	550		2,502	1,075		2,502	2,325	0
Cash paid for acquisitions												(800)			(4,467)	(388)	(1,555)	(4,507)
Cash used in investing activities			(7,351)			(6,406)			(16,396)	(15,918)	(13,503)	(35,021)	(26,572)	(23,705)	(51,126)	(42,846)	(35,303)	(65,939)
Financing activities
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense												175,378			175,254	0	0	175,254
Net proceeds from issuance of long-term debt											267,564	60,000		267,564	60,000	0	267,564	60,000
Cash paid for financing costs											(3,914)	(1,350)		(3,914)	(1,350)	0	(3,914)	(1,350)
Proceeds on term loans, net of deferred financing costs			10,506			4,881			12,282	28,946	11,991	39,764	52,576	34,742	54,706	82,389	49,921	70,590
Payments on long-term debt			(13,060)			(9,689)			(7,462)	(33,198)	(286,525)	(255,806)	(59,903)	(312,800)	(266,040)	(90,428)	(327,331)	(275,243)
Payments of deferred offering costs									(467)
Dividends and dividend equivalents paid			(257)			(271)				(278)	(8,680)	(30,176)	(320)	(8,715)	(30,223)	(332)	(8,729)	(30,241)
Proceeds from exercise of stock options			336			30				396	536		1,157	683		1,398	2,380	170
Repurchases of vested restricted stock awards withheld on net share settlement			(367)							(367)			(421)			(421)	0	0
Common stock repurchases for tax withholdings of net settlement of equity awards												(71)			(356)	(417)	0	(356)
Distributions to noncontrolling interests			(16,718)			(19,044)			(21,440)	(34,189)	(38,542)	(43,973)	(55,131)	(60,509)	(66,985)	(70,960)	(79,478)	(94,468)
Contributions from noncontrolling interests			1,730			1,710			1,884	2,520	2,887	4,441	3,645	3,847	6,576	7,739	6,522	7,470
Purchases of noncontrolling interests			(3,158)			(4,546)				(8,601)	(9,507)	(277)	(8,729)	(27,854)	(8,397)	(9,066)	(29,540)	(8,397)
Proceeds from sales of additional noncontrolling interests			92							92		142	178	66	199	229	66	227
Cash used in financing activities			(20,896)			(26,929)			(15,203)	(44,679)	(64,190)	(51,928)	(66,948)	(106,890)	(76,616)	(79,869)	(122,539)	(96,344)
(Decrease) increase in cash			(7,238)			(16,812)			4,979	(2,118)	(25,883)	2,280	(9,649)	(33,222)	14,156	(16,311)	(29,294)	9,923
Cash at beginning of year	69,493	64,373	71,611	75,022	84,093	100,905	93,262	95,961	90,982	71,611	100,905	90,982	71,611	100,905	90,982	71,611	100,905	90,982
Cash and restricted cash at end of year	61,962	69,493	64,373	67,683	75,022	84,093	105,138	93,262	95,961	69,493	75,022	93,262	61,962	67,683	105,138	55,300	71,611	100,905
As Previously Reported
Operating activities
Net income	18,294	2,277	13,713	26,672	16,391	12,902	36,046	13,042	22,557	15,990	29,293	35,599	34,284	55,965	71,645		75,683	88,205
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization			9,623			9,074			7,677	19,437	18,456	15,929	29,460	27,894	24,616		37,634	33,862
Amortization of discounts, fees and deferred financing costs			497			530			797	989	1,065	1,807	1,384	1,534	2,432		2,031	2,595
Loss on early extinguishment of debt					526			4,708			526	4,708		526	4,708		526	4,708
Stock-based compensation			1,264			10,088			386	2,927	13,731	10,565	4,174	14,762	23,238		15,872	40,285
Premium paid for interest rate cap agreements						(1,186)					(1,186)			(1,186)			(1,186)
Deferred taxes			0			673			67	(5,014)	729	(7,769)	(5,014)	730	(8,508)		8,455	(14,018)
Change in fair value of income tax receivable agreement	3,480	(1,736)	1,021	(3,585)	2,641	(4,517)	(12,565)	7,835		(715)	(1,876)	7,835	2,765	(5,461)	(4,730)		(7,234)	(1,286)
Non-cash charge related to derivative agreements			1			173			623	5	173	850	18	173	489		173	473
Non-cash rent charges			167			289			512	161	431	920	400	588	1,764		1,044	2,191
Loss (gain) on disposal of assets			250			57				279	190		342	(377)			(772)	857
Change in operating assets and liabilities, net of acquisitions:
Accounts receivable			(6,061)			3,632			1,088	(11,846)	3,286	15	(10,934)	(107)	(334)		1,465	(4,208)
Inventories			(2,977)			28			(1,224)	(1,870)	(284)	(499)	(1,717)	4	(177)		11	(385)
Prepaid expenses and other current assets			(457)			(3,870)			(152)	7,119	(9,637)	1,305	6,809	(1,425)	(1,171)		(7,936)	(7,226)
Other assets			(4,311)			(63)			(18)	(8,733)	(552)	692	(7,291)	(558)	44		(1,325)	(219)
Accounts payable			7,464			(6,522)			1,286	19,428	(2,943)	944	20,602	2,736	706		2,294	8,556
Accrued compensation and benefits			(1,825)			(3,011)			(1,008)	1,896	(449)	2,965	5,673	2,664	6,588		(118)	6,599
Accrued expenses and other liabilities			2,640			(1,755)			3,985	18,426	1,407	13,363	2,916	(1,090)	20,593		1,930	11,222
Cash provided by operating activities			21,009			16,522			36,576	58,479	52,360	89,229	83,871	97,372	141,903		128,547	172,211
Investing activities
Purchases of property, equipment and intangible assets			(9,851)			(6,406)			(16,396)	(18,418)	(14,053)	(34,221)	(29,074)	(24,780)	(46,659)		(36,073)	(61,432)
Proceeds from asset sales			2,500							2,500	0		2,502	1,075			2,325
Cash paid for acquisitions												(800)			(4,467)		(1,555)	(4,507)
Cash used in investing activities			(7,351)			(6,406)			(16,396)	(15,918)	(14,053)	(35,021)	(26,572)	(23,705)	(51,126)		(35,303)	(65,939)
Financing activities
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense												175,378			175,254			175,254
Net proceeds from issuance of long-term debt											267,564	60,000		267,564	60,000		267,564	60,000
Cash paid for financing costs											(3,914)	(1,350)		(3,914)	(1,350)		(3,914)	(1,350)
Proceeds on term loans, net of deferred financing costs			10,506			4,881			12,282	28,946	11,991	39,764	52,576	34,742	54,706		49,921	70,590
Payments on long-term debt			(13,060)			(9,689)			(7,462)	(33,198)	(286,525)	(255,806)	(59,903)	(312,800)	(266,040)		(327,331)	(275,243)
Payments of deferred offering costs									(467)
Dividends and dividend equivalents paid			(257)			(271)				(278)	(8,680)	(30,176)	(320)	(8,715)	(30,223)		(8,729)	(30,241)
Proceeds from exercise of stock options			336			30				396	536		1,157	683			2,380	170
Repurchases of vested restricted stock awards withheld on net share settlement			(367)							(367)			(421)
Common stock repurchases for tax withholdings of net settlement of equity awards												(71)			(356)			(356)
Distributions to noncontrolling interests			(16,718)			(19,044)			(21,440)	(34,189)	(38,542)	(43,973)	(55,131)	(60,509)	(66,985)		(79,478)	(94,468)
Contributions from noncontrolling interests			1,730			1,710			1,884	2,520	2,887	4,441	3,645	3,847	6,576		6,522	7,470
Purchases of noncontrolling interests			(3,158)			(4,546)				(8,601)	(9,507)	(277)	(8,729)	(27,854)	(8,397)		(29,540)	(8,397)
Proceeds from sales of additional noncontrolling interests			92							92		142	178	66	199		66	227
Cash used in financing activities			(20,896)			(26,929)			(15,203)	(44,679)	(64,190)	(51,928)	(66,948)	(106,890)	(76,616)		(122,539)	(96,344)
(Decrease) increase in cash			(7,238)			(16,813)			4,977	(2,118)	(25,883)	2,280	(9,649)	(33,223)	14,161		(29,295)	9,928
Cash at beginning of year	69,503	64,383	71,621	75,033	84,103	100,916	93,268	95,965	90,988	71,621	100,916	90,988	71,621	100,916	90,988	71,621	100,916	90,988
Cash and restricted cash at end of year	61,972	69,503	64,383	67,693	75,033	84,103	105,149	93,268	95,965	69,503	75,033	93,268	61,972	67,693	105,149		71,621	100,916
Restatement Adjustments
Operating activities
Net income	(5,782)	(10,660)	(6,549)	(881)	(6,632)	(1,140)	71	8,127	9,433	(17,209)	(7,772)	17,560	(22,991)	(8,653)	17,631		(17,547)	13,461
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization			0			0			0	0	0	0	0	0	0		0	0
Amortization of discounts, fees and deferred financing costs			0			0			0	0	0	0	0	0	0		0	0
Loss on early extinguishment of debt					0			0			0	0		0	0		0	0
Stock-based compensation			0			0			0	0	0	0	0	0	0		0	0
Premium paid for interest rate cap agreements						0					0			0			0
Deferred taxes			(569)			0			(67)	(723)	863	7,860	(870)	881	8,307		2,844	(4,552)
Change in fair value of income tax receivable agreement	0	0	0	0	0	0	0	0		0	0	0	0	0	0		0	0
Non-cash charge related to derivative agreements			0			0			0	0	0	0	0	0	0		0	0
Non-cash rent charges			0			0			0	0	0	0	0	0	0		0	0
Loss (gain) on disposal of assets			(262)			0				(297)	(250)		(261)	62			745	0
Change in operating assets and liabilities, net of acquisitions:
Accounts receivable			8,374			731			(11,420)	19,599	9,265	(22,010)	24,899	9,058	(21,193)		16,103	(17,013)
Inventories			1,513			0			0	0	0	0	1	0	0		0	0
Prepaid expenses and other current assets			291			4,668			87	(781)	5,091	(2,542)	452	2,909	2,007		1,583	2,458
Other assets			(2)			0			0	0	0	0	0	0	0		0	0
Accounts payable			0			0			0	0	0	0	0	0	0		0	0
Accrued compensation and benefits			0			0			0	0	0	0	0	0	0		0	0
Accrued expenses and other liabilities			(2,796)			(4,258)			1,969	(589)	(7,747)	(868)	(1,230)	(4,256)	(6,757)		(3,727)	5,641
Cash provided by operating activities			0			1			2	0	(550)	0	0	1	(5)		1	(5)
Investing activities
Purchases of property, equipment and intangible assets			0			0			0	0	0	0	0	0	0		0	0
Proceeds from asset sales			0							0	550		0	0			0
Cash paid for acquisitions												0			0		0	0
Cash used in investing activities			0			0			0	0	550	0	0	0	0		0	0
Financing activities
Proceeds from issuance of common stock sold in initial public offering, net of underwriting discounts and offering expense												0			0			0
Net proceeds from issuance of long-term debt											0	0		0	0		0	0
Cash paid for financing costs											0	0		0	0		0	0
Proceeds on term loans, net of deferred financing costs			0			0			0	0	0	0	0	0	0		0	0
Payments on long-term debt			0			0			0	0	0	0	0	0	0		0	0
Payments of deferred offering costs									0
Dividends and dividend equivalents paid			0			0				0	0	0	0	0	0		0	0
Proceeds from exercise of stock options			0			0				0	0		0	0			0	0
Repurchases of vested restricted stock awards withheld on net share settlement			0							0			0
Common stock repurchases for tax withholdings of net settlement of equity awards												0			0			0
Distributions to noncontrolling interests			0			0			0	0	0	0	0	0	0		0	0
Contributions from noncontrolling interests			0			0			0	0	0	0	0	0	0		0	0
Purchases of noncontrolling interests			0			0				0	0	0	0	0	0		0	0
Proceeds from sales of additional noncontrolling interests			0							0		0	0	0	0		0	0
Cash used in financing activities			0			0			0	0	0	0	0	0	0		0	0
(Decrease) increase in cash			0			1			2	0	0	0	0	1	(5)		1	(5)
Cash at beginning of year	(10)	(10)	(10)	(11)	(10)	(11)	(6)	(4)	(6)	(10)	(11)	(6)	(10)	(11)	(6)	$ (10)	(11)	(6)
Cash and restricted cash at end of year	$ (10)	$ (10)	$ (10)	$ (10)	$ (11)	$ (10)	$ (11)	$ (6)	$ (4)	$ (10)	$ (11)	$ (6)	$ (10)	$ (10)	$ (11)		$ (10)	$ (11)

SCHEDULE II - VALUATION AND Q_2

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for uncollectible accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of the Year	$ 8,676	$ 9,733	$ 9,563
Amounts charged to income	0	17,745	19,503
Amounts written off	(5,406)	(20,560)	(17,575)
Balance at End of Year	$ 3,270	$ 8,676	$ 9,733