Pension and Employee Benefit Plans - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions	$ 29,000	$ 400,000
Unfunded liability plans	11,000,000		$ 11,000,000
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Anticipated contribution to fund the pension plan during the reminder of the fiscal year	0
Health Care Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Anticipated contribution to fund the pension plan during the reminder of the fiscal year	$ 25,000