Leases and Leases Commitments - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2019
Lessee Lease Description [Line Items]
Options to extend the leases	5 years		5 years
Operating cash flows used for operating leases			$ 20,659
Total operating lease expense	$ 9,500	$ 7,400	18,900	$ 15,000
Short-term leases expense	800		2,100
Operating lease assets	$ 171,000		$ 171,000
Operating Lease Right Of Use Asset Statement Of Financial Position Extensible List	us-gaap:OtherAssetsMember		us-gaap:OtherAssetsMember
Mooring Equipment [Member]
Lessee Lease Description [Line Items]
Operating lease payments, lease not yet commenced			$ 12,000
Lease term of lease expected to commence in September 2019	9 years 6 months		9 years 6 months
ASU 2016-02 [Member]
Lessee Lease Description [Line Items]
Operating lease assets					$ 146,800
ASU 2016-02 [Member] | Sale and Lease-back Equipment [Member]
Lessee Lease Description [Line Items]
Operating lease term	10 years		10 years
Options to extend the leases	5 years		5 years
Operating cash flows used for operating leases			$ 26,000
Sale lease back transaction renewal term description			Renewal options for two successive five-year periods.
Sale leaseback transaction service period			ten-year
ASU 2016-02 [Member] | Prepaid Expenses and Other Current Assets [Member]
Lessee Lease Description [Line Items]
Prepaid rent					3,900
ASU 2016-02 [Member] | Other Assets [Member]
Lessee Lease Description [Line Items]
Prepaid rent					$ 10,600
Minimum [Member]
Lessee Lease Description [Line Items]
Operating lease term	1 month		1 month
Maximum [Member]
Lessee Lease Description [Line Items]
Operating lease term	10 years		10 years
Options to terminate the leases			1 year