Stockholders' Equity - Adjustments for Items Reclassified Out of AOCI (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Amortization of interest rate hedge		$ 2,502	$ 1,055
Amortization relating to employee benefit plans	6,672	6,534
Less - related income taxes	1,923	1,929	1,145
Net of tax	4,749	4,605	4,399
Total reclassifications, net of tax	$ 4,749	$ 7,107