CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		3 Months Ended				6 Months Ended				9 Months Ended				12 Months Ended
		Mar. 31, 2016		Mar. 31, 2015		Jun. 30, 2016		Jun. 30, 2015		Sep. 30, 2016		Sep. 30, 2015		Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014
OPERATING ACTIVITIES
Net income		$ 5,953	[1]	$ 5,293	[1]	$ 13,624	[1]	$ 13,250	[1]	$ 19,758	[1]	$ 20,224	[1]	$ 26,268	$ 26,489	[1]	$ 25,314	[1]
Adjustments to reconcile net income including non-controlling interests to net cash provided by operating activities:
Depreciation and amortization		2,091	[1]	1,807	[1]	4,158	[1]	3,674	[1]	6,210	[1]	5,656	[1]	8,779	7,952	[1]	6,740	[1]
Provision for doubtful accounts		1,089	[1]	990	[1]	2,045	[1]	2,052	[1]	2,962	[1]	3,119	[1]	4,040	4,170	[1]	4,112	[1]
Equity-based awards compensation expense		1,221	[1]	991	[1]	2,484	[1]	2,206	[1]	3,748	[1]	3,368	[1]	4,962	4,491	[1]	3,363	[1]
Loss on sale of fixed assets		(19)	[1]	17	[1]	0	[1]	(13)	[1]	31	[1]	3	[1]	152	84	[1]	35	[1]
Excess tax benefit from equity-based awards		142	[1]	(271)	[1]	0	[1]	(430)	[1]	0	[1]	(816)	[1]	0	(947)	[1]	(948)	[1]
Deferred income tax		1,823	[1]	473	[1]	2,503	[1]	2,056	[1]	3,238	[1]	2,918	[1]	2,979	5,953	[1]	5,106	[1]
Other		0	[1]	34	[1]	0	[1]	111	[1]	0	[1]	180	[1]	0	180	[1]	135	[1]
Changes in operating assets and liabilities:
Increase in patient accounts receivable		(2,185)	[1]	(2,185)	[1]	(2,449)	[1]	(2,880)	[1]	(2,548)	[1]	(4,148)	[1]	(3,275)	(5,519)	[1]	(5,388)	[1]
(Increase) decrease in accounts receivable - other		43	[1]	125	[1]	53	[1]	165	[1]	116	[1]	(145)	[1]	(400)	(852)	[1]	341	[1]
(Increase) decrease in other assets		(2,282)	[1]	106	[1]	(2,443)	[1]	(13)	[1]	(4,979)	[1]	(1,485)	[1]	(1,399)	(1,375)	[1]	1,155	[1]
Increase (decrease) in accounts payable and accrued expenses		3,392	[1]	(5,976)	[1]	6,603	[1]	(3,958)	[1]	3,582	[1]	(3,766)	[1]	2,994	(7,011)	[1]	1,868	[1]
Increase in mandatorily redeemable non-controlling interests		2,578	[1]	406	[1]	4,028	[1]	90	[1]	5,372	[1]	683	[1]	5,598	2,509	[1]	2,936	[1]
Increase (decrease) in other liabilities		365	[1]	665	[1]	447	[1]	927	[1]	708	[1]	380	[1]	352	1,396	[1]	(3,378)	[1]
Net cash provided by operating activities		14,211	[1]	2,475	[1]	31,053	[1]	17,237	[1]	38,198	[1]	26,171	[1]	51,050	37,520	[1]	41,391	[1]
INVESTING ACTIVITIES
Purchase of fixed assets		(1,738)	[1]	(1,419)	[1]	(3,453)	[1]	(2,873)	[1]	(5,620)	[1]	(4,690)	[1]	(8,260)	(6,263)	[1]	(5,167)	[1]
Purchase of businesses, net of cash acquired		(12,899)	[1]	(6,445)	[1]	(12,958)	[1]	(14,467)	[1]	(12,958)	[1]	(14,434)	[1]	(23,623)	(18,965)	[1]	(12,270)	[1]
Acquisitions of non-controlling interests		(388)	[1]	(359)	[1]	(250)	[1]	(968)	[1]	(664)	[1]	(942)	[1]	(670)	(968)	[1]	(227)	[1]
Proceeds on sale of fixed assets, net		42	[1]	8	[1]	42	[1]	72	[1]	42	[1]	71	[1]	61	71	[1]	47	[1]
Net cash used in investing activities		(14,983)	[1]	(8,215)	[1]	(16,619)	[1]	(18,236)	[1]	(19,200)	[1]	(19,995)	[1]	(32,492)	(26,125)	[1]	(17,617)	[1]
FINANCING ACTIVITIES
Distributions to non-controlling interests		(1,113)	[1]	(1,045)	[1]	(2,893)	[1]	(2,904)	[1]	(4,441)	[1]	(4,148)	[1]	(5,718)	(5,892)	[1]	(5,963)	[1]
Cash dividends to shareholders - funded		(2,125)	[1]			(4,254)	[1]	(3,723)	[1]	(6,382)	[1]	(5,586)	[1]	(8,510)	(7,449)	[1]	(5,873)	[1]
Proceeds from revolving line of credit		49,000	[1]	34,000	[1]	93,000	[1]	51,000	[1]	128,000	[1]	75,000	[1]	168,000	103,000	[1]	134,300	[1]
Payments on revolving line of credit		(40,500)	[1]	(27,000)	[1]	(94,500)	[1]	(44,500)	[1]	(136,000)	[1]	(63,500)	[1]	(166,000)	(93,500)	[1]	(139,800)	[1]
Payments to settle mandatorily redeemable non-controlling interests		(1,136)	[1]			(1,136)	[1]			(1,136)	[1]	(1,860)	[1]	(1,262)	(6,115)	[1]	(5,233)	[1]
Principal payments on notes payable		(250)	[1]	(200)	[1]	(533)	[1]	(608)	[1]	(592)	[1]	(616)	[1]	(800)	(884)	[1]	(825)	[1]
Tax benefit from equity-based awards		323	[1]	271	[1]	556	[1]	430	[1]	798	[1]	816	[1]	0	947	[1]	948	[1]
Other		1	[1]			1	[1]	5	[1]	1	[1]	5	[1]	1	5	[1]	45	[1]
Net cash (used in) provided by financing activities		4,200	[1]	6,026	[1]	(9,759)	[1]	(300)	[1]	(19,752)	[1]	111	[1]	(14,289)	(9,888)	[1]	(22,401)	[1]
Net increase in cash and cash equivalents		3,428	[1]	286	[1]	4,675	[1]	(1,299)	[1]	(754)	[1]	6,287	[1]	4,269	1,507	[1]	1,373	[1]
Cash and cash equivalents - beginning of period	[1]	15,778		14,271		15,778		14,271		15,778		14,271		15,778	14,271		12,898
Cash and cash equivalents - end of period		19,206	[1]	14,557	[1]	20,453	[1]	12,972	[1]	15,024	[1]	20,558	[1]	20,047	15,778	[1]	14,271	[1]
Cash paid during the period for:
Income taxes		2,265	[1]	1,275	[1]	5,513	[1]	3,835	[1]	10,051	[1]	5,659	[1]	10,584	7,779	[1]	9,253	[1]
Interest		248	[1]	235	[1]	512	[1]	460	[1]	770	[1]	616	[1]	784	884	[1]	1,103	[1]
Non-cash investing and financing transactions during the period:
Purchase of business - seller financing portion		500	[1]	$ 500	[1]	500	[1]	$ 1,350	[1]	500	[1]	1,350	[1]	1,000	1,800	[1]	400	[1]
Acquisition of noncontrolling interest - seller financing portion		388	[1]			388	[1]			388	[1]	0	[1]	387	0	[1]	0	[1]
Payment to settle redeemable non-controlling interest - financing portion		$ 126	[1]			126	[1]			126	[1]	$ 1,240	[1]	127	3,077	[1]	67	[1]
Receivable from sale of non-controlling interests						$ (148)	[1]			$ (148)	[1]			$ (138)	$ 0	[1]	$ 0	[1]

[1] as restated