Disclosures About Fair Value - Fair Value of Assets and Liabilities on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets
Available-for-sale Securities	$ 22,853	$ 25,071
Fair Value, Measurements, Recurring
Assets
Available-for-sale equity securities	18,477	20,689
Available-for-sale debt securities	4,376	4,382
Available-for-sale Securities	22,853	25,071
Fair Value, Measurements, Recurring | Quoted Prices In Active Markets for Identical Assets (Level 1)
Assets
Available-for-sale equity securities	10,580	12,545
Available-for-sale debt securities	4,376	4,382
Available-for-sale Securities	14,956	16,927
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Available-for-sale equity securities	7,897	8,144
Available-for-sale debt securities
Available-for-sale Securities	$ 7,897	$ 8,144