Building Improvements Program and Agreement to Extend Lease - Additional Information (Detail) (USD $)	12 Months Ended						12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2000	Dec. 31, 1999	Nov. 05, 2009 Second Mortgage [Member]	Nov. 29, 2004 First Mortgage [Member]	Dec. 31, 2012 Forecast [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2004 Maximum [Member]	Dec. 31, 2012 Minimum [Member]
Real Estate Activity [Line Items]
Building improvement program costs		$ 28,000,000	$ 22,800,000			$ 100,000,000		$ 100,000,000
Actual improvement Cost	78,263,624
Debt instrument amount	$ 100,000,000			$ 16,000,000	$ 84,000,000		$ 100,000,000
Lease expiration date	Sep. 30, 2033						Sep. 30, 2083		Sep. 30, 2033