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

No definition available.

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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Period Type:	instant

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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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.

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- Definition

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.

+ References

No definition available.

+ 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.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Balance Type:	credit
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- Definition

The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

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Debt - Additional Information (Detail) - USD ($)	1 Months Ended	9 Months Ended	12 Months Ended
Debt - Additional Information (Detail) - USD ($)	Oct. 31, 2018	Sep. 30, 2019	Dec. 31, 2018
Discretionary Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 250,000,000
Debt term		30 days
Borrowings outstanding		$ 0	$ 0
3.75% Senior Notes due 2021
Debt Instrument [Line Items]
Debt, stated interest rate		3.75%
2.45% Senior Notes due 2027
Debt Instrument [Line Items]
Debt, stated interest rate		2.45%
4.20% Senior Notes due 2048
Debt Instrument [Line Items]
Debt, stated interest rate		4.20%
6 5/8% Senior Notes due 2029
Debt Instrument [Line Items]
Debt, stated interest rate		6.625%
6.25% Senior Notes due 2032
Debt Instrument [Line Items]
Debt, stated interest rate		6.25%
4.35% Senior Notes due 2044
Debt Instrument [Line Items]
Debt, stated interest rate		4.35%
3.70% Senior Notes due 2045
Debt Instrument [Line Items]
Debt, stated interest rate		3.70%
4.125% Senior Notes due 2047
Debt Instrument [Line Items]
Debt, stated interest rate		4.125%
4.00% Senior Notes due 2029
Debt Instrument [Line Items]
Debt, face amount	$ 550,000,000
Debt, stated interest rate	4.00%	4.00%
Proceeds, net of underwriter's discounts and commissions	$ 544,500,000
Federal Funds Open Rate \| Discretionary Line of Credit
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		0.50%