Represents the percentage of debt discount that was originally recognized at the issuance of the instrument.

No definition available.

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- Definition

The principal amount of notes used as denominator for purposes of computing the conversion ratio of convertible debt.

+ References

No definition available.

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- Definition

Debt Issuance Cost Amortization Period

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No definition available.

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- Definition

Percentage of Underwriting Fee

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No definition available.

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- Definition

Represents the percentage of principal amount used in computation of the redemption price to be paid on conversion of convertible notes at the request of the debt holders and upon the occurrence of a designated event.

+ References

No definition available.

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- Definition

Represents the number of days of written notice to be made to the holders of the notes required for redemption.

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No definition available.

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- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
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- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instruments must exceed threshold percentage for a specified number of trading days to trigger conversion feature, 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

Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

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- Definition

Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

+ References

No definition available.

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- Definition

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

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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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/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

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

+ References

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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

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
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- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

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- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ 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.

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- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of debt issuance costs (for example, but not limited to, legal, accounting, broker, and regulatory fees).

+ References

No definition available.

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Exchangeable Senior Notes - Additional Information (Detail)			1 Months Ended	3 Months Ended	12 Months Ended
	Sep. 15, 2015 USD ($)	Jun. 21, 2013 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) d	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
2.375% Exchangeable Senior Notes due 2033 (the 2013 Notes) [Member]
Debt Instrument [Line Items]
Notes exchange, threshold percentage				130.00%
Notes exchange, threshold trading days \| d				20
Notes exchange, threshold consecutive trading days				30 days
Effective interest rate on the liability component				4.00%	4.00%
2.375% Exchangeable Senior Notes due 2033 (the 2013 Notes) [Member] \| Operating Partnership [Member]
Debt Instrument [Line Items]
Principal amount of notes issued		$ 250,000,000		$ 85,364,000	$ 85,364,000
Interest rate		2.375%		2.375%	2.375%
Issuance cost	$ 605,000	$ 1,672,000
Conversion ratio, number of shares per $1,000 principal amount, numerator					18.18
Principal amount used for debt instrument conversion ratio				$ 1,000	$ 1,000
Redemption price as percentage of principal amount of notes plus accrued and unpaid interest		100.00%
Redemption price as percentage of principal amount of notes at request of debt holders and upon occurrence of designated event		100.00%
Discount rate (as a percent)		1.50%
Amortization period		5 years
Unamortized cash discount	6,931,000	$ 3,750,000		$ 633,000	$ 633,000	$ 2,606,000
Principal amount repurchased	164,636,000
Total cash paid for repurchase	$ 227,212,000
Exchangeable Senior Notes 3.125% due 2035 (the 2015 Notes) [Member]
Debt Instrument [Line Items]
Effective interest rate on the liability component				4.00%	4.00%
Exchangeable Senior Notes 3.125% due 2035 (the 2015 Notes) [Member] \| Operating Partnership [Member]
Debt Instrument [Line Items]
Principal amount of notes issued			$ 575,000,000	$ 575,000,000	$ 575,000,000
Interest rate			3.125%	3.125%	3.125%
Issuance cost			$ 11,992,000
Underwriting fee percentage			2.00%
Amortization period			5 years
Conversion ratio, number of shares per $1,000 principal amount, numerator					10.48
Principal amount used for debt instrument conversion ratio				$ 1,000	$ 1,000
Redemption price as percentage of principal amount of notes plus accrued and unpaid interest			100.00%
Redemption price as percentage of principal amount of notes at request of debt holders and upon occurrence of designated event			100.00%
Minimum [Member] \| 2.375% Exchangeable Senior Notes due 2033 (the 2013 Notes) [Member] \| Operating Partnership [Member]
Debt Instrument [Line Items]
Number of days of written notice to holders of notes required for redemption		30 days
Minimum [Member] \| Exchangeable Senior Notes 3.125% due 2035 (the 2015 Notes) [Member] \| Operating Partnership [Member]
Debt Instrument [Line Items]
Number of days of written notice to holders of notes required for redemption			30 days
Maximum [Member] \| 2.375% Exchangeable Senior Notes due 2033 (the 2013 Notes) [Member] \| Operating Partnership [Member]
Debt Instrument [Line Items]
Number of days of written notice to holders of notes required for redemption		60 days
Maximum [Member] \| Exchangeable Senior Notes 3.125% due 2035 (the 2015 Notes) [Member] \| Operating Partnership [Member]
Debt Instrument [Line Items]
Number of days of written notice to holders of notes required for redemption			60 days