Reclassifications Out of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 20,851	$ 20,034
Tax benefit	14,528	19,710
Earnings from Continuing Operations	2,125	1,674
Pension and Postretirement Benefit Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings from Continuing Operations	1,910	1,473
Unamortized Value of Terminated Forward Starting Interest Rate Swap
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Earnings from Continuing Operations	215	201
Reclassification out of Accumulated Other Comprehensive Income | Pension and Postretirement Benefit Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Settlement charge		59
Prior service credit	(357)	(374)
Actuarial loss	3,452	2,732
Tax benefit	(1,185)	(944)
Earnings from Continuing Operations	1,910	1,473
Reclassification out of Accumulated Other Comprehensive Income | Pension and Postretirement Benefit Plans | Nonoperating Expenses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications out of accumulated other comprehensive loss before taxes	3,095	2,417
Reclassification out of Accumulated Other Comprehensive Income | Unamortized Value of Terminated Forward Starting Interest Rate Swap
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	356	332
Tax benefit	(141)	(131)
Earnings from Continuing Operations	$ 215	$ 201