CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 275	$ 22,194
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	63,495	55,980
Amortization of operating lease right-of-use assets	31,601	34,055
Equity in earnings of joint ventures, net of dividends	6,096	(5,266)
Amortization of deferred financing costs and loan discount	1,494	1,295
Loss on sale and disposal of equipment and other	656	1,209
Amortization of cash flow hedge, net of taxes	1,844	1,847
Non-cash change in fair value of interest rate hedge	(66)	(27,125)
Stock-based compensation	17,055	15,795
Change in fair value of contingent consideration	3,098	(1,287)
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in purchase transactions:
Accounts receivable	(8,124)	(30,566)
Other current assets	4,703	(709)
Other assets	(6,590)	1,282
Deferred taxes	(2,249)	4,732
Operating lease liability	(28,582)	(32,219)
Deferred revenue	1,033	(7,565)
Accounts payable, accrued expenses and other	14,952	32,092
Net cash provided by (used in) operating activities	100,691	65,744
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of imaging centers and other acquisitions	(10,315)	(26,009)
Purchase of property and equipment	(95,380)	(72,659)
Proceeds from sale of equipment	73	4,121
Equity contributions in existing and purchase of interest in joint ventures	(288)	(1,441)
Net cash provided by (used in) investing activities	(105,910)	(95,988)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on notes payable	(1,052)	0
Payments on term loan debt	(7,376)	(6,625)
Distributions paid to noncontrolling interests	(3,523)	0
Proceeds from issuance of common stock, net of issuance costs	246,202	0
Proceeds from issuance of common stock upon exercise of options	51	0
Net cash provided by (used in) financing activities	234,302	(6,625)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	(266)	1,433
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	228,817	(35,436)
CASH AND CASH EQUIVALENTS, beginning of period	127,834	134,606
CASH AND CASH EQUIVALENTS, end of period	356,651	99,170
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid during the period for interest	39,301	19,687
Cash paid during the period for income taxes	$ 201	$ 126