Derivative Financial Instruments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014 Cash Flow Hedging [Member]	Dec. 31, 2013 Cash Flow Hedging [Member]	Mar. 31, 2014 Derivative in Fair Value Hedging Relationship [Member]	Dec. 31, 2013 Derivative in Fair Value Hedging Relationship [Member]
Derivative [Line Items]
LIBOR period	3 months
Weighted average fixed rate	6.14%
Notional amount of interest		$ 30.5	$ 30.5	$ 100.1	$ 95.3
Recorded period of effectiveness of cash flow hedges on net income	12 months
Recorded period of effectiveness of fair value hedges on net income	12 months
Recorded period of effectiveness of fair value of derivatives on net income	12 months