The percentage of the principal amount of the bonds which was paid by the investors.

No definition available.

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- Definition

Net increase or decrease in the carrying amount of the debt instrument for the period.

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

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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Contractual interest rate for funds borrowed, under the debt agreement.

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-Topic 210
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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.

+ References

No definition available.

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- Definition

The cash outflow for the extinguishment of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity.

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

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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Notes Payable - Note Issuances (Details) - Notes Payable - USD ($)	1 Months Ended				12 Months Ended
	Apr. 30, 2018	Dec. 31, 2017	Mar. 31, 2017	Oct. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
3.875% notes, issued in April 2018 and due in April 2025
Debt
Interest rate (as a percent)					3.875%
Principal amount issued					$ 500,000,000
Public offering price (as a percent)					99.50%
Effective yield (as a percent)					3.96%
Proceeds from issuance of debt	$ 493,100,000
Notes issued in March 2017
Debt
Proceeds from issuance of debt			$ 705,200,000
4.125% notes, issued in March 2017 and due in October 2026
Debt
Interest rate (as a percent)		4.125%				4.125%
Principal amount issued			400,000,000			$ 400,000,000
Public offering price (as a percent)		102.98%				102.98%
Effective yield (as a percent)		3.75%				3.75%
4.650% notes, issued in March 2017 and due in March 2047
Debt
Interest rate (as a percent)		4.65%				4.65%
Principal amount issued			$ 300,000,000			$ 300,000,000
Public offering price (as a percent)		99.97%				99.97%
Effective yield (as a percent)		4.65%				4.65%
Notes issued in December 2017
Debt
Proceeds from issuance of debt		$ 1,300,000,000
3.250% notes, issued in December 2017 and due in October 2022
Debt
Interest rate (as a percent)		3.25%				3.25%
Principal amount issued		$ 500,000,000				$ 500,000,000
Public offering price (as a percent)		101.77%				101.77%
Effective yield (as a percent)		2.84%				2.84%
3.650% notes, issued in December 2017 and due in January 2028
Debt
Interest rate (as a percent)		3.65%			3.65%	3.65%
Principal amount issued						$ 550,000,000
Public offering price (as a percent)		99.78%				99.78%
Effective yield (as a percent)		3.68%				3.68%
4.650% notes, issued in December 2017 and due in March 2047
Debt
Interest rate (as a percent)		4.65%				4.65%
Principal amount issued		$ 250,000,000				$ 250,000,000
Public offering price (as a percent)		105.43%				105.43%
Effective yield (as a percent)		4.32%				4.32%
3.000% notes, issued in October 2016 and due in January 2027
Debt
Interest rate (as a percent)		3.00%			3.00%	3.00%	3.00%
Principal amount issued							$ 600,000,000
Public offering price (as a percent)							98.67%
Effective yield (as a percent)							3.15%
Proceeds from issuance of debt				$ 586,700,000
6.750% notes, issued in September 2007 and due in August 2019
Debt
Interest rate (as a percent)		6.75%				6.75%
Early repayment of notes payable		$ 550,000,000