Derivatives - Summary of Gains and Losses on Derivative Contracts (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (losses) on derivative contract	$ (100)	$ 7	$ 464	$ 13
Interest Rate Swaps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (losses) on derivative contract	15	5	21	12
Equity Options [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (losses) on derivative contract			615
Foreign Exchange Swaps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (losses) on derivative contract	$ (115)	$ 2	$ (172)	$ 1