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- Definition

Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
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-Section 13
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Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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-Publisher SEC
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- Definition

For an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

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- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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- Definition

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

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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- Definition

The average strike price on the group of price risk option contracts such as put options or call options.

+ References

No definition available.

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- Definition

Stated rate on an interest rate forward or futures contract.

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No definition available.

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- Definition

The forward price on the price risk forward or futures contract, such as a gas futures contract.

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No definition available.

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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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No definition available.

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- Definition

Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Amount of gain recognized in the income statement from the hedging ineffectiveness of a fair value hedge.

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- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

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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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- Definition

Amount after tax, before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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- Definition

Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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Financial instruments - Additional Information (Detail)			6 Months Ended	12 Months Ended
Financial instruments - Additional Information (Detail)	Mar. 24, 2017 USD ($)	Oct. 25, 2016 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($) $ / MWh	Dec. 31, 2017 USD ($)	Jan. 01, 2019 CAD ($) $ / MWh	Jan. 31, 2017 USD ($)	Jan. 31, 2014 USD ($)	Dec. 31, 2012 USD ($)
Derivative [Line Items]
Other comprehensive income, foreign currency loss				$ 37,204,000	$ (17,817,000)
Other comprehensive income, foreign currency translation adjustment gain (loss)				$ (27,969,000)	(21,753,000)
Revenue collection period				45 days
Cash on hand				$ 46,819,000
Available for drawn on senior debt facilities				1,046,826,000
Utility Services
Derivative [Line Items]
Accounts receivable balances				207,740,000
Liberty Power Group
Derivative [Line Items]
Other comprehensive income, foreign currency translation adjustment gain (loss)				41,244,000	19,063,000
Bonds \| Plan
Derivative [Line Items]
Debt instrument, term			10 years
Long-term debt			$ 135,000,000
Senior Debt
Derivative [Line Items]
Long-term debt					479,000,000
Par value	$ 750,000,000
Senior Unsecured Notes
Derivative [Line Items]
Long-term debt				3,336,795,000	3,079,551,000
Senior Unsecured Notes \| Liberty Power Group \| 4.82% Senior Unsecured Notes
Derivative [Line Items]
Par value									$ 150,000,000
Senior Unsecured Notes \| Liberty Power Group \| 4.65% Senior Unsecured Notes
Derivative [Line Items]
Par value								$ 200,000,000
Senior Unsecured Notes \| Liberty Power Group \| Convertible Unsecured Subordinated Debentures
Derivative [Line Items]
Par value							$ 300,000,000
Ten Year Foreign Exchange Forward
Derivative [Line Items]
Term of forward-starting interest rate swap		10 years
Notional amount		$ 250,000,000
Derivative, forward interest rate		1.8395%
Thirty Year Foreign Exchange Forward
Derivative [Line Items]
Term of forward-starting interest rate swap		30 years
Notional amount		$ 250,000,000
Derivative, forward interest rate		2.5539%
Forward contracts
Derivative [Line Items]
Other comprehensive income, foreign currency loss				1,115,000	$ (297,000)
Cash flow hedge \| Interest rate swaps
Derivative [Line Items]
Term of forward-starting interest rate swap			10 years
Hedge ineffectiveness recognized in earnings				$ 898,000
Minimum
Derivative [Line Items]
Forward price \| $ / MWh				14.55
Minimum \| Senior Debt
Derivative [Line Items]
Debt instrument, term	3 years
Maximum
Derivative [Line Items]
Forward price \| $ / MWh				172.97
Maximum \| Senior Debt
Derivative [Line Items]
Debt instrument, term	30 years
Weighted Average
Derivative [Line Items]
Forward price \| $ / MWh				24.72
Non-regulated Energy Sales
Derivative [Line Items]
Unrealized gains currently in accumulated other comprehensive loss to be reclassified into net earnings within next twelve months				$ 6,289,000
Interest expense
Derivative [Line Items]
Unrealized gains currently in accumulated other comprehensive loss to be reclassified into net earnings within next twelve months				$ 989,000
Accounts Receivable [Member] \| Credit Concentration Risk [Member] \| Liberty Power Group
Derivative [Line Items]
Percentage of revenue contributed				83.98471%
Subsequent Event \| Bonds
Derivative [Line Items]
Long-term debt						$ 135,000,000
Subsequent Event \| Interest Rate Contract [Member]
Derivative [Line Items]
Notional amount						$ 300,000,000
Derivative, forward interest rate						4.60%
Minonk Wind Facility \| Subsequent Event \| Cash flow hedge
Derivative [Line Items]
Notional quantity (MW-hrs) \| $ / MWh						251,581,000
Receive average prices (per MW-hr) \| $ / MWh						20.72