Condensed Results of Operations of Mammoth Pacific (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Condensed statements of operations:
Company's equity in income of Mammoth: 50% of Mammoth net income	$ (69,000)	$ 479,000	$ (481,000)	$ 1,025,000
Income tax benefit	1,007,000	3,365,000	421,000	5,922,000
Net income (loss) attributable to the Company's stockholders	8,133,000	(1,437,000)	(842,000)	401,000
Mammoth Pacific
Condensed statements of operations:
Revenues				9,806,000
Gross margin				2,842,000
Net income				2,720,000
Company's equity in income of Mammoth: 50% of Mammoth net income				1,360,000
Plus amortization of basis difference				296,000
Equity Method Investment Summarized Financial Information Income (loss) Before Income Taxes, Total				1,656,000
Income tax benefit				(629,000)
Net income (loss) attributable to the Company's stockholders				$ 1,027,000