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No definition available.

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- Definition

Senior Notes, Net of Deferred Finance Costs

+ References

No definition available.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
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- Definition

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

+ References

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
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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.

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- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Corporate Indebtedness - Senior Unsecured Notes (Details) - USD ($)	1 Months Ended	3 Months Ended
	Oct. 31, 2017	Mar. 31, 2018	Dec. 31, 2017
Debt disclosures by scheduled maturity date
Accreted Balance		$ 1,491,922,000	$ 1,491,575,000
Senior unsecured notes
Debt disclosures by scheduled maturity date
Unpaid Principal Balance		1,400,000,000
Accreted Balance		1,404,406,000	1,404,605,000
Deferred financing costs, net		(8,086,000)	(8,666,000)
Accreted Balance, net of deferred financing costs		1,396,320,000	1,395,939,000
Senior unsecured notes \| 5.00% Senior unsecured notes maturing on August 15, 2018
Debt disclosures by scheduled maturity date
Unpaid Principal Balance		250,000,000
Accreted Balance		$ 249,972,000	249,953,000
Coupon Rate (as a percent)		5.00%
Initial Term (in Years)		7 years
Senior unsecured notes \| 7.75% Senior unsecured notes maturing on March 15, 2020
Debt disclosures by scheduled maturity date
Unpaid Principal Balance		$ 250,000,000
Accreted Balance		$ 250,000,000	250,000,000
Coupon Rate (as a percent)		7.75%
Initial Term (in Years)		10 years
Senior unsecured notes \| 4.50% Senior unsecured notes maturing on December 1, 2022
Debt disclosures by scheduled maturity date
Unpaid Principal Balance		$ 300,000,000
Accreted Balance		$ 304,920,000	305,163,000
Coupon Rate (as a percent)		4.50%
Initial Term (in Years)		10 years
Senior unsecured notes \| 4.27% Senior unsecured notes maturing on December 17, 2025
Debt disclosures by scheduled maturity date
Unpaid Principal Balance		$ 100,000,000
Accreted Balance		$ 100,000,000	100,000,000
Coupon Rate (as a percent)		4.27%
Initial Term (in Years)		10 years
Senior unsecured notes \| 3.25 Percent Senior Unsecured Notes Due October 2022
Debt disclosures by scheduled maturity date
Unpaid Principal Balance		$ 500,000,000
Accreted Balance		$ 499,514,000	$ 499,489,000
Coupon Rate (as a percent)		3.25%
Initial Term (in Years)		5 years
Senior Unsecured Bonds \| 4.50% Senior Unsecured Bonds Due December 2022
Debt disclosures by scheduled maturity date
Coupon Rate (as a percent)	4.50%
Face amount of loan	$ 100,000,000.0
Redemption price, percentage	105.334%