4. EARNINGS PER SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Earning Per Share
Net loss attributable to Radnet, Inc.'s common stockholders	$ (1,342)	$ (111)
Weighted average number of common shares outstanding during the year	39,314,447	37,669,921
Basic and diluted net loss per share attributable to Radnet, Inc.'s common stockholders	$ (0.03)	$ 0.00