Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Unrealized gain on available-for-sale marketable securities, net of taxes	$ 1,656	$ (533)	$ 791	$ 1,416	$ 1,123	$ 2,207
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proceeds from available for sale municipal bonds					5,779	7,145
Realized loss					(100)
Realized gain					100
Unrealized gains related to equity securities	6,700		1,600		1,000	5,000
Municipal bonds — available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proceeds from available for sale municipal bonds	4,000		3,600		5,800	7,100
Realized loss	$ (100)				$ (100)
Realized gain			$ 100			$ 100