CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities:
Net income	$ 26,108	$ 21,638
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	6,348	5,911
Provision for bad debts	5,044	8,383
Stock-based compensation expense	3,077	2,236
Deferred income taxes	2,522	2,058
Loss on disposal of assets	154	1,247
Changes in operating assets and liabilities, net of acquisitions:
Receivables	(6,970)	(19,758)
Prepaid expenses and other assets	(2,329)	(6,446)
Prepaid income taxes	(3,296)	(4,364)
Accounts payable and accrued expenses	15,119	21,867
Income taxes payable	(3,499)
Net amounts due to/from governmental entities	498	(1,900)
Net cash provided by operating activities	42,776	30,872
Investing activities:
Purchases of property, building and equipment	(5,341)	(13,712)
Cash paid for acquisitions, primarily goodwill and intangible assets	(22,704)	(11,515)
Advanced payments on acquisitions	(523)
Other		273
Net cash used in investing activities	(28,568)	(24,954)
Financing activities:
Proceeds from line of credit	19,000	35,000
Payments on line of credit	(22,000)	(23,000)
Proceeds from employee stock purchase plan	469	445
Payments on debt	(129)	(115)
Noncontrolling interest distributions	(5,167)	(4,338)
Excess tax benefits from vesting of stock awards		1,218
Withholding taxes paid on stock-based compensation	(2,744)	(1,703)
Purchase of additional controlling interest	(184)
Sale of noncontrolling interest	251	52
Proceeds from exercise of stock options	0	109
Net cash (used in) provided by financing activities	(10,504)	7,668
Change in cash	3,704	13,586
Cash at beginning of period	3,264	6,139
Cash at end of period	6,968	19,725
Supplemental disclosures of cash flow information:
Interest paid	1,762	1,489
Income taxes paid	$ 17,320	$ 10,635