Leases - Maturities Of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of 2020	$ 32,967
2020		$ 66,820
2021	59,945	60,452
2022	57,199	57,363
2023	39,142	39,202
2024	6,766	6,819
Thereafter	5,937	6,251
Total lease payments	201,956	236,907
Less: imputed interest	(23,950)	(31,295)
Total operating lease liabilities	178,006	205,612
Current operating lease liabilities	53,023	53,785
Non-current operating lease liabilities	124,983	151,827
Vessels
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of 2020	29,916
2020		60,210
2021	54,347	54,564
2022	52,106	52,106
2023	34,580	34,580
2024	2,470	2,470
Thereafter	0	0
Total lease payments	173,419	203,930
Less: imputed interest	(18,665)	(24,846)
Total operating lease liabilities	154,754	179,084
Current operating lease liabilities	48,351	48,716
Non-current operating lease liabilities	106,403	130,368
Facilities and Equipment
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of 2020	3,051
2020		6,610
2021	5,598	5,888
2022	5,093	5,257
2023	4,562	4,622
2024	4,296	4,349
Thereafter	5,937	6,251
Total lease payments	28,537	32,977
Less: imputed interest	(5,285)	(6,449)
Total operating lease liabilities	23,252	26,528
Current operating lease liabilities	4,672	5,069
Non-current operating lease liabilities	$ 18,580	$ 21,459

Amount of lessee's undiscounted obligation for lease payment for operating lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease due after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease having initial or remaining lease term in excess of one year to be paid in remainder of current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980

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- Definition

Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.

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- References

No definition available.

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Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.

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