Share-Based Payments - Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 9,138		$ 30,280	$ 23,414
Share-based compensation	$ 15,168	$ 15,112	9,138	$ 14,275
Additional Paid-In Capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	15,168	$ 15,112	9,138	$ 14,275
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	2,662		2,376		5,444	5,507
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	7,673		6,588		14,031	13,950
Performance awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 4,833		$ 174		$ 10,805	$ 3,957