Monthly Principal Amortization Requirements (Detail) (USD $)	6 Months Ended
	Jun. 30, 2012
May 2010 through April 2011
Expected Amortization Expense [Line Items]
Monthly amortization	$ 50,000
May 2011 through April 2012
Expected Amortization Expense [Line Items]
Monthly amortization	70,000
May 2012 through April 2013
Expected Amortization Expense [Line Items]
Monthly amortization	90,000
May 2013 through April 2014
Expected Amortization Expense [Line Items]
Monthly amortization	100,000
May 2014
Expected Amortization Expense [Line Items]
Monthly amortization	$ 50,000