Effective date of securities under the shelf registration statement.

No definition available.

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- Definition

Expiry date of securities remaining under the shelf registration statement.

+ References

No definition available.

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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
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
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-Publisher FASB
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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- 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
-SubTopic 10
-Section S99
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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

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
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585

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- Definition

The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Paragraph 14
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- Definition

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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Debt - Notes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Shelf registration statement effective date	Jun. 28, 2016
Shelf registration statement expiry date	Jun. 28, 2019
Repayments of notes payable		$ 497,975	$ 1,500,000
3.50% Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of unsecured debt	$ 500,000
Debt instrument, interest rate, stated percentage	3.50%
Proceeds from debt, net of issuance costs	$ 497,000
Debt instrument, interest rate, effective percentage	3.61%
4.15% Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of unsecured debt	$ 400,000
Debt instrument, interest rate, stated percentage	4.15%
Proceeds from debt, net of issuance costs	$ 399,300
Debt instrument, interest rate, effective percentage	3.85%
5.75 % Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		5.75%
Repayments of notes payable		$ 394,100
7.125% Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		7.125%
Repayments of notes payable		$ 103,900
3.25% Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of unsecured debt		$ 400,000
Debt instrument, interest rate, stated percentage		3.25%
Proceeds from debt, net of issuance costs		$ 399,300
Debt instrument, interest rate, effective percentage		3.32%
4.00% Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of unsecured debt		$ 300,000
Debt instrument, interest rate, stated percentage		4.00%
Proceeds from debt, net of issuance costs		$ 293,200
Debt instrument, interest rate, effective percentage		4.11%