Accumulated Other Comprehensive Loss - Summary of Reclassifications from Accumulated Other Comprehensive Loss to Net Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Amortization of defined benefit plan pension items:
Amortization of loss	$ 63	$ 273	$ 497	$ 819
Income tax effect	(26)	(112)	(204)	(336)
After tax	37	161	293	483
Loss on cash flow hedges - interest rate swaps:
Reclassification to interest expense	27		80	1,970
Income tax effect	(11)		(33)	(810)
After tax	16		47	1,160
Total reclassifications, net of income tax	$ 53	$ 161	$ 340	$ 1,643