Fair Value Measurements - Contractual Maturities of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Maturing in one year or less	$ 1,133	$ 876
Maturing in second year through fifth year	21,489	16,071
Maturing in sixth year through tenth year	42,400	38,801
Maturing after ten years	25,475	34,963
Total debt securities	$ 90,497	$ 90,711

Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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