Fair Value Disclosures - Contingent Consideration Liability Change in Amount (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Change in Contingent Consideration Liability [Roll Forward]
Beginning balance	$ 259	$ 339
Contingent consideration from new acquisition	0	0
Payment of contingent consideration	129	131
Adjustment of contingent consideration	30	51
Ending balance	160	259
Girard Partners [Member]
Change in Contingent Consideration Liability [Roll Forward]
Beginning balance	259	339
Contingent consideration from new acquisition	0	0
Payment of contingent consideration	129	131
Adjustment of contingent consideration	30	51
Ending balance	$ 160	$ 259