Employee Benefit Plans - Fair Value of Pension Plan Assets by Asset Category (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	$ 2,690	$ 2,806
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets		3
Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	1,041	1,119
Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	1,649	1,684
Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	2,690	2,806
Fair Value, Inputs, Level 1 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets		3
Fair Value, Inputs, Level 1 | Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	1,041	1,119
Fair Value, Inputs, Level 1 | Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets	$ 1,649	$ 1,684