Accumulated Other Comprehensive Income (Loss) - Change in Accumulated Other Comprehensive Income (Loss) (AOCI) by Component, Net of Tax (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
AOCI, balance as of December 31, 2016			$ 781,106
Other comprehensive income (loss) before reclassifications			1,402
Amounts reclassified from AOCI			1,515
Total other comprehensive income (loss), net of tax	$ 1,760	$ 7,960	2,917	$ 11,039
AOCI, balance as of June 30, 2017	593,679		593,679
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
AOCI, balance as of December 31, 2016			(8,439)
Other comprehensive income (loss) before reclassifications			1,477
Total other comprehensive income (loss), net of tax			1,477
AOCI, balance as of June 30, 2017	(6,962)		(6,962)
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
AOCI, balance as of December 31, 2016			172
Other comprehensive income (loss) before reclassifications			(75)
Amounts reclassified from AOCI			107
Total other comprehensive income (loss), net of tax			32
AOCI, balance as of June 30, 2017	204		204
Defined Benefit Pension Plans [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
AOCI, balance as of December 31, 2016			(38,189)
Amounts reclassified from AOCI			1,408
Total other comprehensive income (loss), net of tax			1,408
AOCI, balance as of June 30, 2017	(36,781)		(36,781)
AOCI, Total [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
AOCI, balance as of December 31, 2016			(46,456)
AOCI, balance as of June 30, 2017	$ (43,539)		$ (43,539)