Financial Instruments - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014 Derivative	Dec. 31, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Unrealized loss of hedging instrument	$ 1,100,000
Unrealized gain of hedging instrument		13,900,000
Approximate fair value of notes	362,200,000	148,200,000
Carrying amount of notes	358,200,000	145,500,000
Tax Increment Financing Bonds ("TIF Bonds")	3,751,000	5,086,000
Aggregate notional amount	530,000,000	631,400,000
Number of interest rate derivatives held	9
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net	$ (5,900,000)