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

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=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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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

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

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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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No definition available.

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- Definition

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

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- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

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- Definition

Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond 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))
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-Section S99
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- Definition

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

+ References

No definition available.

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- Definition

The cash outflow for a borrowing supported by a written promise to pay an obligation.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Debt - Notes - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Unsecured notes	$ 5,143,248,000		$ 4,848,079,000
Repayments of Notes Payable	$ 394,077,000	$ 1,500,000,000
Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Aug. 01, 2047
Weighted Average Interest Rate	4.41%
Notes Payable, Other Payables [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.375%
Notes Payable, Other Payables [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.57%
5.75 % Notes [Member]
Debt Instrument [Line Items]
Repayments of Notes Payable	$ 394,100,000
Debt Instrument, Interest Rate, Stated Percentage	5.75%
3.25% Notes [Member]
Debt Instrument [Line Items]
Public Notes, Face Value	$ 400,000,000
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Proceeds from Debt, Net of Issuance Costs	$ 399,300,000
Debt Instrument, Interest Rate, Effective Percentage	3.32%
4.00% Notes [Member]
Debt Instrument [Line Items]
Public Notes, Face Value	$ 300,000,000
Debt Instrument, Interest Rate, Stated Percentage	4.00%
Proceeds from Debt, Net of Issuance Costs	$ 293,200,000
Debt Instrument, Interest Rate, Effective Percentage	4.11%