Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Remaining Fiscal Year

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- Definition

Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Four

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- Definition

Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Three

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- Definition

Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Two

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Number of debt instruments.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount of unamortized debt discount (premium) and debt issuance costs.

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of cash inflow before closing and debt issuance costs received by a seller-lessee in a sale-leaseback recognized in financing activities.

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Long-Term Debt - Summary of Long-Term Debt (Details)	9 Months Ended		12 Months Ended
Long-Term Debt - Summary of Long-Term Debt (Details)	Sep. 30, 2019 USD ($) credit_facility	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
Proceeds from financing related to sales and leaseback of vessels (note 8)	$ 63,720,000	$ 156,644,000
Total principal	612,877,000		$ 741,992,000
Less: unamortized discount and debt issuance costs	(3,917,000)		(6,586,000)
Total debt	608,960,000		735,406,000
Less: current portion	(101,295,000)		(106,236,000)
Non-current portion of long-term debt	507,665,000		629,170,000
Term Loans
Debt Instrument [Line Items]
Total principal	248,947,000		323,995,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total principal	$ 363,930,000		417,997,000
Revolving Credit Facilities Due through 2022 [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Number Of Debt Instruments \| credit_facility	2
Line of Credit Facility, Remaining Borrowing Capacity	$ 18,400,000		11,800,000
Line of Credit Facility, Maximum Borrowing Capacity	382,300,000.0		$ 429,800,000.0
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Remaining Fiscal Year	3,000,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Two	12,100,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Three	304,800,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Four	$ 62,400,000
Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	3.50%
Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.30%
London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member] \| Term Loans
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.00%		2.00%
London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.75%		2.75%
London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member] \| Term Loans
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.30%		0.30%
London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.00%		2.00%