Deferred Consideration - Schedule of Deferred Consideration (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Contractual gold payments	$ 4,105	$ 4,250	$ 13,001	$ 12,834
Contractual gold payments – gold ounces paid	2,375	2,375	7,125	7,125
Gain/(loss) on revaluation of deferred consideration – gold payments	$ 77,895	$ 1,737	$ 63,188	$ 5,066