Deferred Compensation - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Deferred Compensation Obligations	$ 2,429	$ 2,243
other Assets	10,811	9,173
Liability outstanding	438	538
Charges to operations	48	48
cash value	13,400	13,732
Proceeds from life insurance	856
Gain on life insurance benefit	120
Rabbi Trust Accounts [Member]
other Assets	$ 2,429	$ 2,243