CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 28,640	$ 43,005
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	85,209	71,272
Amortization of operating lease right-of-use assets	51,573	55,880
Equity in earnings of joint ventures, net of dividends	(8,350)	(8,259)
Amortization of deferred financing costs and loan discount	1,943	2,608
Loss (gain) on sale and disposal of equipment and other	962	(279)
Loss on extinguishment of debt	0	1,496
Amortization of cash flow hedge, net of taxes	2,771	2,765
Non-cash change in fair value of interest rate swaps	(39,576)	(14,149)
Stock-based compensation	19,112	21,566
Change in fair value of contingent consideration	(329)	891
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in purchase transactions:
Accounts receivable	(36,686)	(23,237)
Other current assets	(4,934)	3,358
Other assets	3,738	(4,998)
Deferred taxes	8,955	10,124
Operating lease liability	(49,597)	(55,035)
Deferred revenue	(7,809)	(19,438)
Accounts payable, accrued expenses and other	37,148	12,725
Net cash provided by operating activities	92,770	100,295
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of imaging centers and other acquisitions	(26,009)	(70,108)
Purchase of property and equipment	(98,606)	(88,478)
Proceeds from sale of equipment	3,008	521
Equity contributions in existing and purchase of interest in joint ventures	(1,441)	(1,441)
Net cash used in investing activities	(123,048)	(159,506)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on notes and leases payable	0	(3,302)
Payments on term loan debt	(9,938)	(616,217)
Proceeds from debt refinancing, net of issuing costs	0	716,369
Proceeds from sale of economic interest in majority owned subsidiary, net of taxes	0	11,602
Proceeds from revolving credit facility	0	128,300
Payments on revolving credit facility	0	(128,300)
Proceeds from issuance of common stock upon exercise of options	0	26
Net cash (used in) provided by financing activities	(9,938)	108,478
EFFECT OF EXCHANGE RATE CHANGES ON CASH	616	(32)
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(39,600)	49,235
CASH AND CASH EQUIVALENTS, beginning of period	134,606	102,018
CASH AND CASH EQUIVALENTS, end of period	95,006	151,253
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid during the period for interest	30,251	21,408
Cash paid during the period for income taxes	$ 560	$ 1,913