Leases - Components of lease expense, and lease assets and liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Lease Cost
Amortization of right-to-use assets (included in depreciation expense)	$ 711
Interest on lease liabilities	548
Operating lease cost	17,014
Short-term lease cost	566
Variable lease cost	1,899
Total lease cost	20,738
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from finance lease	578
Operating cash flows from operating leases	15,169
Financing cash flows from finance lease	1,168
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	15,501
Assets and Liabilities, Lessee [Abstract]
Finance lease right-of-assets (included in other assets)	$ 2,311
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other, net
Operating lease right-of-use assets	$ 76,859	$ 0
Finance liability, current (included in current installments of long-term debt)	$ 1,325
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Long Term Debt And Capital Lease Obligations Current
Finance lease liability, noncurrent (included in long-term debt)	$ 3,654
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long Term Debt And Capital Lease Obligations
Operating lease liability, current (included in other accrued liabilities)	$ 11,043
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Liabilities, Current
Operating lease liability, noncurrent	$ 67,898	$ 0
Weighted average remaining lease term finance leases	3 years 6 months
Weighted average remaining lease term operating leases	10 years 2 months 12 days
Weighted average discount rate finance leases	10.10%
Weighted average discount rate operating leases	4.70%