Additional number of term loan credit facilities.

No definition available.

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- Definition

Amount outstanding under new term loan facilities.

+ References

No definition available.

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- Definition

Number Of Revolving Credit Facilities

+ References

No definition available.

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- Definition

Number of senior notes issued.

+ References

No definition available.

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- Definition

Number Of Term Loan Credit Facilities

+ References

No definition available.

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- Definition

Price Per Senior Note

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No definition available.

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- Definition

Repayment of term loan credit facility.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

Term Loan Line Of Credit Facility Description

+ References

No definition available.

+ Details

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- Definition

Terminated portion of term loan facility.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

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

+ References

No definition available.

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- Definition

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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- Definition

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

+ 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.

+ References

No definition available.

+ Details

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

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Data Type:	xbrli:dateItemType
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- Definition

Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

+ References

+ Details

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- Definition

Earliest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

+ References

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- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

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Balance Type:	credit
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- Definition

Description of the terms of a credit facility arrangement. Terms typically include interest rate, collateral required, guarantees required, repayment requirements, and restrictions on use of assets and activities of the entity.

+ References

+ Details

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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.

+ References

+ Details

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Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

+ References

+ Details

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- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ Details

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- Definition

The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3255-108585

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Long-term debt - Schedule of Long-Term Debt (Parenthetical) (Detail)		12 Months Ended
	Apr. 03, 2014 USD ($) Note $ / Note	Dec. 31, 2015 USD ($) CreditFacility	Dec. 31, 2014 USD ($)	Apr. 22, 2015 USD ($)	Dec. 31, 2013 USD ($)
Debt Instrument [Line Items]
Weighted average rate of interest, including the margin		4.50%	3.90%
Senior unsecured notes issued (note 8(c))			$ 345,000,000
Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Interest rate on debt instrument	6.375%
Issuance of senior unsecured notes \| Note	13,800,000
Debt instrument price per share \| $ / Note	25.00
Senior unsecured notes issued (note 8(c))	$ 345,000,000
Notes, maturity date		Apr. 30, 2019
Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
Credit facilities, maximum aggregate borrowings		$ 2,216,352,000	2,075,499,000
Credit facilities, aggregate borrowings undrawn		$ 231,250,000	$ 340,000,000
Credit facility maturity start date		Dec. 11, 2016
Credit facility maturity end date		Jul. 06, 2025
Weighted average rate of interest, including the margin		3.00%	2.80%
Number of term loan credit facilities \| CreditFacility		15
Terminated portion of term loan facility		$ 97,500,000
Term Loan payments, Description		The Term Loan payments are made in quarterly or semi-annual payments commencing three, six or thirty-six months after delivery of the associated newbuilding containership or utilization date.
Term loan, outstanding principal		$ 90,000,000
Repayment of credit facility	$ 125,000,000
Term Loan Credit Facilities [Member] \| Export-Import Bank Of Korea [Member]
Debt Instrument [Line Items]
Interest rate margin		0.70%
Term loan principal outstanding amount		$ 103,832,000
Minimum [Member] \| Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
Commitment fee on undrawn amount		0.70%
Maximum [Member] \| Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
Commitment fee on undrawn amount		0.80%
One Month LIBOR [Member] \| Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
LIBOR interest rate		0.30%	0.20%
LIBOR plus margin [Member] \| Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
Credit facilities, maximum aggregate borrowings		$ 702,700,000
Interest rate description		interest is calculated as one month, three month or six month LIBOR plus a margin per annum
Debt instrument description		At December 31, 2015, the one month, three month and six month LIBOR was 0.3%, 0.5% and 0.5%, respectively (2014 – 0.2%, 0.2% and 0.3%, respectively) and the margins ranged between 0.4% and 4.8% (2014 – 0.4% and 4.8%).
Additional number of term loan credit facilities \| CreditFacility		5
Amounts drawn under term loan facilities		$ 366,577,000
Term loan principal outstanding amount		$ 1,881,270,000
LIBOR plus margin [Member] \| Minimum [Member] \| Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
Interest rate margin		0.40%	0.40%
LIBOR plus margin [Member] \| Maximum [Member] \| Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
Interest rate margin		4.80%	4.80%
Three Month LIBOR [Member] \| Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
LIBOR interest rate		0.50%	0.20%
Six Month LIBOR [Member] \| Term Loan Credit Facilities [Member]
Debt Instrument [Line Items]
LIBOR interest rate		0.50%	0.30%
Revolving Credit Facilities [Member]
Debt Instrument [Line Items]
Number of long-term revolving credit facilities \| CreditFacility		4
Credit facilities, maximum aggregate borrowings		$ 1,227,115,000	$ 1,307,046,000
Credit facilities, aggregate borrowings undrawn		170,022,000	$ 5,126,000
Revolving credit facility amount outstanding		$ 93,240,000			$ 1,000,000,000
Credit facility maturity start date		Apr. 30, 2016
Credit facility maturity end date		Dec. 31, 2023
Interest rate description		Interest is calculated as one month LIBOR plus a margin per annum
Debt instrument description		At December 31, 2015, the one month LIBOR was 0.3% (2014 – one month and three month LIBOR 0.2%) and the margins ranged between 0.5% and 1.3% (2014 – 0.5% and 1.3%)
Weighted average rate of interest, including the margin		0.90%	0.80%
Description of the terms of a credit facility arrangement		The Revolver loan payments are made in semi-annual payments commencing six or thirty-six months after delivery of the associated newbuilding containership for the secured facilities
Revolving Credit Facilities [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Interest rate margin		0.50%	0.50%
Commitment fee on undrawn amount		0.20%
Revolving Credit Facilities [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Interest rate margin		1.30%	1.30%
Commitment fee on undrawn amount		0.40%
Revolving Credit Facilities [Member] \| One Month LIBOR [Member]
Debt Instrument [Line Items]
LIBOR interest rate		0.30%
Revolving Credit Facilities [Member] \| One and Three Month LIBOR [Member]
Debt Instrument [Line Items]
LIBOR interest rate			0.20%
Three Hundred And Sixty Four Day Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facilities, maximum aggregate borrowings				$ 200,000,000
Revolving credit facility amount outstanding		$ 35,000,000