Leases - Operating lease ROU assets, operating lease liabilities and other supplemental information (Details) $ in Thousands	Mar. 31, 2020 USD ($)
Operating leases:
Operating lease right-of-use assets	$ 50,180
Accrued expenses	7,955
Long-term operating lease liabilities	$ 74,912
Weighted-average remaining lease term (years)	10 years 5 months 8 days
Weighted-average discount rate	3.83%