Maximum term of the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 55
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-URI http://asc.fasb.org/extlink&oid=6409961&loc=d3e20487-108367

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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Gross number of share options (or share units) granted during the period.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Value, before forfeitures, of stock or other type of equity granted of any equity-based compensation plan other than an employee stock ownership plan (ESOP).

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Gross number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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Capital Stock - Share-based Compensation of Subsidiaries (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended	9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares or units issued related to the exercise of share based compensation during the period (in shares)				200,000
Stock options granted (in shares)				1,048,916	732,314
Stock option per share value (in usd per share)				$ 8.67	$ 10.18
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares or units granted equity based compensation awards (in shares)				625,878	344,319
Vesting period				3 years
Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
Teekay Offshore \| Phantom unit awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares or units granted equity based compensation awards (in shares)				1,424,058	321,318
Teekay Offshore \| Non-management directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares or units issued related to the exercise of share based compensation during the period (in shares)				293,770	56,950
Teekay LNG \| Phantom unit awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares or units granted equity based compensation awards (in shares)				62,283	60,809
Teekay LNG \| Non-management directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares or units issued related to the exercise of share based compensation during the period (in shares)				17,498	17,345
Teekay Tankers \| Restricted stock units \| Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares or units granted equity based compensation awards (in shares)				762,640	382,437
Teekay Tankers \| Non-management directors \| Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares or units issued related to the exercise of share based compensation during the period (in shares)				168,029	0
Teekay Tankers \| Non-management directors \| Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	504,097	396,412
Teekay Tankers \| Officer \| Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Stock options granted (in shares)	736,327	486,329
Stock option per share value (in usd per share)	$ 1.22		$ 2.23
Maximum contractual term	10 years
Teekay Offshore Teekay Lng And Teekay Tankers \| Restricted stock and phantom share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common units aggregate value, granted				$ 5.8	$ 3.5
Vesting period				3 years
Teekay Offshore Teekay Lng And Teekay Tankers \| Non-management directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common units aggregate value, granted				$ 1.3	$ 0.6