Leases - Additional information regarding leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Lessee, Lease, Description [Line Items]
Operating lease costs	$ 30,478	$ 27,600	$ 31,100
Cash payments included in the measurement of lease liabilities reported in operating cash flows	27,521
Right-of-use assets obtained in exchange for new lease liabilities	7,445
Operating lease liability	$ 150,519
Weighted average discount rate	3.90%
Weighted average remaining lease term	6 years 4 months 24 days
Other assets
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 131,661
Other liabilities
Lessee, Lease, Description [Line Items]
Operating lease liability	$ 150,519
Maximum
Lessee, Lease, Description [Line Items]
Operating lease term	11 years