Leases - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Lessee, Lease, Description [Line Items]
Restricted funds	$ 62,671	$ 28,340	$ 57,956
Lease Agreements
Lessee, Lease, Description [Line Items]
Letters of credit outstanding, amount	3,600
Restricted funds	$ 3,600	$ 3,600