Fair Value of Assets and Liabilities - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - Fair Value Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2019		Dec. 31, 2018
Assets
Equity investments	$ 10,079		$ 9,197
Available for sale investment securities	48,998	[1]	45,324	[2]
Total	59,077		54,521
Level 2 [Member]
Assets
Available for sale investment securities	48,998	[1]	45,324	[2]
Total	48,998		45,324
Level 3 [Member]
Assets
Equity investments	10,079		9,197
Total	$ 10,079		$ 9,197

[1] Total unrealized gains of $1,081, net of tax, was included in accumulated other comprehensive income (loss) for the twelve months ended December 31, 2019 related to these assets.

[2] Total unrealized losses of $82, net of tax, was included in accumulated other comprehensive income (loss) for the nine months ended December 31, 2018 related to these assets.