Other Income, net - Summary of Other Income, net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other Income and Expenses [Abstract]
Gain on sale and mark-to-market of mutual funds, net	$ 3,109	$ 3,318	$ 5,166	$ 6,844
Interest income	632	697	1,164	1,493
Others, net	484	87	424	188
Other income, net	$ 4,225	$ 4,102	$ 6,754	$ 8,525