5. INVESTMENT IN JOINT VENTURES (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Key financial data for joint ventures
Current assets - joint ventures	$ 15,277
Noncurrent assets - joint ventures	44,169
Current liabilities - joint ventures	(5,537)
Noncurrent liabilities - joint ventures	(5,871)
Total net assets -joint ventures	48,038
Book value of Radnet joint venture interests	22,422
Cost in excess of book value of acquired joint venture interests	5,232
Elimination of intercompany profit remaining on Radnet's consolidated balance sheet	305
Total value of Radnet joint venture interests	27,959
Total book value of other joint venture partner interests	25,616
Net revenue	22,281	21,076
Net income	$ 2,733	$ 2,533

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Total book value of other joint venture partner interests

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Total value of Radnet joint venture interests

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This element represents the aggregate cost of investments accounted for under the equity method of accounting.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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The amount of assets reported by an equity method investment of the entity.

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The amount of current assets reported by an equity method investment of the entity.

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The amount of current liabilities reported by an equity method investment of the entity.

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The amount of liabilities reported by an equity method investment of the entity.

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This item represents the entity's ownership percentage in the investee multiplied by the investee's total equity.

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This item represents the amount of unrealized intercompany profits and losses on transactions between the Entity and unconsolidated subsidiaries (including certain corporate joint ventures, and noncontrolled corporations), accounted for under the equity method of accounting, which have not been eliminated in preparing the Entity's financial statements.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

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