Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities
Net income (loss)	$ (36,627)	$ 15,583	$ 99
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	41,224	35,102	32,468
Amortization of deferred financing costs and debt discount	682	879	1,531
Equity-based compensation	86,745	8,034	9,787
Extinguishment of debt	1,750	2,894	7,922
Provision for doubtful accounts	521	289	400
Impairment charges			2,579
Loss on disposal of property and equipment	307	1,719	274
Deferred income taxes	(1,300)	(4,807)	4,453
Changes in assets and liabilities:
Accounts receivable	(8,317)	(2,420)	(3,380)
Other receivables	(329)	(623)	(596)
Prepaid expenses and other assets	(1,859)	1,319	(406)
Accounts payable	(225)	(3)	(2,785)
Accrued payroll and related liabilities	3,774	678	3,770
Accrued expenses and other liabilities	388	342	121
Deferred revenue	3,594	(5,183)	(1,782)
Income taxes receivable	(1,687)	965	(544)
Net cash provided by operating activities	88,641	54,768	53,911
Investing activities
Acquisitions of businesses, net of cash acquired	(12,146)	(28,177)	(2,813)
Purchases of property and equipment	(26,197)	(19,414)	(17,230)
Net cash used in investing activities	(38,343)	(47,591)	(20,043)
Financing activities
Proceeds from the issuance of long‑term debt	185,000	41,825	50,000
Payments on long‑term debt	(410,769)	(67,662)	(55,337)
Deferred financing payments	(3,441)	(508)	(851)
Payments on capital lease obligations	(5,385)	(3,297)	(1,641)
Contingent purchase consideration			(124)
Proceeds from sale of equity interests	100	500	1,189
Purchases of equity interests	(731)	(3,708)	(2,314)
Taxes paid for net settlements of restricted stock vesting	(12,736)
Distribution payments	(8,500)
Proceeds from the issuance of common stock in initial public offering, net of fees	234,437
Net cash used in financing activities	(22,025)	(32,850)	(9,078)
Net increase (decrease) in cash	28,273	(25,673)	24,790
Cash at beginning of period	6,962	32,635	7,845
Cash at end of period	35,235	6,962	32,635
Supplemental disclosure of cash flow information
Cash paid during the period for interest	10,500	18,888	22,858
Cash paid during the period for income taxes	10,329	16,933	2,195
Disposal of property and equipment acquired through capital leases	333
Property and equipment acquired through capital leases	3,357	10,117	1,680
Purchase of property and equipment in accounts payable	$ 2,782	$ 6,459	$ 911