Financial Instruments - Summary of Effects of Interest Rate Swap (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivatives, Fair Value [Line Items]
Gain Recognized in AOCL, net of tax	$ 34	$ 61	$ 79	$ 117
Interest Rate Swap [Member] | Interest Expense [Member]
Derivatives, Fair Value [Line Items]
Gain Recognized in AOCL, net of tax	34	61	79	117
Loss Reclassified from AOCL into Expense	$ 55	$ 109	$ 128	$ 226