Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses, net of current portion	$ 22,418	$ 191
Equity method investments	15,795	15,795	$ 13,449
Cloud computing arrangements	6,385	0
Other investments	2,527	2,123
Other	7,803	3,679
Balance at end of period	$ 54,928	$ 21,788