CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 8,638	$ 1,685	$ 2,376
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	60,611	59,258	58,890
Provision for bad debts	36,033	29,807	27,911
Equity in earnings of joint ventures	(8,927)	(6,970)	(6,194)
Distributions from joint ventures	7,731	7,358	7,204
Amortization and write off of deferred financing costs and loan discount	5,369	5,732	4,565
Loss on sale and disposal of equipment	866	1,113	1,032
Loss on early extinguishment of Senior Notes	0	15,927	0
Gain on sale of imaging centers	(5,434)	0	(2,108)
Stock-based compensation	7,647	2,500	2,574
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in purchase transactions:
Accounts receivable	(34,514)	(43,973)	(31,531)
Other current assets	(14,198)	(5,514)	(2,243)
Other assets	(3,813)	(281)	260
Deferred taxes	4,036	655	2,907
Deferred rent	7,011	2,180	3,871
Deferred revenue	(366)	620	71
Accounts payable and accrued expenses and other	(3,653)	(9,093)	(3,163)
Net cash provided by operating activities	67,037	61,004	66,422
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of imaging facilities	(90,792)	(9,428)	(7,223)
Purchase of property and equipment	(42,964)	(41,740)	(48,623)
Proceeds from sale of equipment	1,282	1,088	635
Proceeds from sale of imaging facilities	35,500	0	3,920
Proceeds from sale of joint venture interests	0	0	2,640
Proceeds from sale of internal use software	443	0	0
Equity contributions in existing and purchase of interest in joint ventures	(265)	(3,562)	(2,009)
Net cash used in investing activities	(96,796)	(53,642)	(50,660)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on notes and leases payable	(9,773)	(23,913)	(9,764)
Proceeds from borrowings	74,400	210,000	35,122
Payments on Senior Notes	(23,727)	(211,344)	0
Deferred financing costs	(531)	(6,650)	(432)
Net (payments) proceeds on revolving credit facility	(15,300)	15,300	(33,000)
Dividends paid to noncontrolling interests	(729)	(148)	(18)
Proceeds from the sale of non-controlling interests	5,005	0	0
Purchase on non-controlling interests	0	(196)	0
Proceeds from issuance of common stock upon exercise of options/warrants	594	1,546	469
Net cash provided by (used in) financing activities	29,939	(15,405)	(7,623)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	(41)	(62)	(89)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	139	(8,105)	8,050
CASH AND CASH EQUIVALENTS, beginning of period	307	8,412	362
CASH AND CASH EQUIVALENTS, end of period	446	307	8,412
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid during the period for interest	36,028	41,584	41,841
Cash paid during the period for income taxes	1,781	1,070	1,142
SUPPLEMENTAL SCHEDULE OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Purchase of equipment and leasehold improvements not yet paid for	32,400	$ 19,400	$ 16,700
Capital lease debt related to radiology equipment	$ 7,800