2. SUMMARY OF ACCOUNTING POLICIES (Details - Investment in Joint Ventures) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equity Method Investments and Joint Ventures [Abstract]
Beginning balance				$ 32,123				$ 28,949	$ 32,123	$ 28,949
Purchase of a 49% interest in a new joint venture										2,168
Equity contributions in existing joint ventures									265	1,394
Equity earnings in these joint ventures	$ 2,626	$ 1,992	$ 3,207	$ 1,102	$ 2,248	$ 2,009	$ 1,646	$ 1,067	8,927	6,970	$ 6,194
Distribution of earnings									(7,731)	(7,358)	(7,204)
Ending balance	$ 33,584				$ 32,123				$ 33,584	$ 32,123	$ 28,949