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