Other Assets, Net - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Finite lived intangible assets, amortization expense	$ 6,000	$ 169,000
Finite lived intangible assets, weighted average amortization period	17 years	14 years 3 months 18 days