Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Details) - Recurring - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Assets
Mutual funds	$ 96,481	$ 160,441
Derivative financial instruments	12,191	16,688
Total	108,672	177,129
Liabilities
Derivative financial instruments	1,733	464
Total	1,733	464
Level 1
Assets
Mutual funds	96,481	160,441
Derivative financial instruments	0	0
Total	96,481	160,441
Liabilities
Derivative financial instruments	0	0
Total	0	0
Level 2
Assets
Mutual funds	0	0
Derivative financial instruments	12,191	16,688
Total	12,191	16,688
Liabilities
Derivative financial instruments	1,733	464
Total	1,733	464
Level 3
Assets
Mutual funds	0	0
Derivative financial instruments	0	0
Total	0	0
Liabilities
Derivative financial instruments	0	0
Total	$ 0	$ 0