Fair Value Measurements - Financial Assets and Liabilities Measured and Reported at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Assets
Available-for-sale security	$ 3,725	$ 3,530	$ 7,150
Total assets	41,182	18,532	27,271
Level 1
Assets
Available-for-sale security	3,725	3,530	7,150
Total assets	3,725	3,530	7,150
Level 2
Assets
Available-for-sale security	0	0	0
Total assets	37,457	15,002	20,121
Level 3
Assets
Available-for-sale security	0	0	0
Total assets	0	0	0
Foreign currency forward exchange contracts and other
Assets
Foreign currency forward exchange contracts and other	37,457	15,002	20,121
Liabilities
Foreign currency forward exchange contracts and other	11,166	2,976	6,183
Foreign currency forward exchange contracts and other | Level 1
Assets
Foreign currency forward exchange contracts and other	0	0	0
Liabilities
Foreign currency forward exchange contracts and other	0	0	0
Foreign currency forward exchange contracts and other | Level 2
Assets
Foreign currency forward exchange contracts and other	37,457	15,002	20,121
Liabilities
Foreign currency forward exchange contracts and other	11,166	2,976	6,183
Foreign currency forward exchange contracts and other | Level 3
Assets
Foreign currency forward exchange contracts and other	0	0	0
Liabilities
Foreign currency forward exchange contracts and other	$ 0	$ 0	$ 0