Acquisitions - 2022 Acquisition (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 13, 2022	Dec. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Net gain on foreign currency transactions		$ 4,628		$ 0	$ 0
Busuu Online S.L.
Business Acquisition [Line Items]
Ownership percent of stock acquired	100.00%
Acquisition related expenses		600		5,300
Amount initially funded	$ 417,000
Fair value of purchase consideration	421,700
Net gain on foreign currency transactions	4,600
Contingent consideration arrangements	$ 25,500
Contingent purchase consideration, cash		7,300	$ 7,300
Revenue since acquisition			38,100
Net loss since acquisition			$ (38,900)
Pro forma revenues		767,600		820,200
Pro forma net income (loss)		$ 268,000		$ (44,700)