Pension and Other Postretirement Employee Benefit Plans - Additional Information (Detail 1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost					$ 5,300
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year			$ 0
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contribution			200
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year			400
Non Qualified Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	$ (1,317)	$ (1,869)	(3,934)	$ (4,466)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost	1,585	5,415	4,752	9,351
Employer contribution			0	0
Cost of Sales [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	200	100	500	800
Selling, General and Administrative Expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	$ 100	$ 100	$ 300	$ 600