Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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- Definition

Average cap rate on a group of interest rate derivatives, such as interest rate caps or collars. If market rates exceed the cap rate, a payment or receipt is triggered on the contract.

+ References

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- Definition

Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Average variable interest rate related to the group of interest rate derivatives.

+ 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

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Derivative Instruments and Hedging Activities Schedule of Interest Rate Caps (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional	$ 41,330,283,000	$ 28,618,861,000	$ 31,226,878,000	$ 24,113,321,000	$ 16,988,116,000	$ 18,802,500,000
Interest Rate Cap [Member] \| Long [Member]
Derivative [Line Items]
Notional	$ 2,500,000,000
Derivative, Average Cap Interest Rate	1.28%
Weighted Average Variable Interest Rate	2.356%
Weighted Average Remaining Maturity	1 year 3 months 14 days
Derivative Maturity Over One And Within Two Years From Balance Sheet Date [Member] \| Interest Rate Cap [Member] \| Long [Member]
Derivative [Line Items]
Notional	$ 800,000,000
Derivative, Average Cap Interest Rate	1.344%
Weighted Average Variable Interest Rate	2.339%
Weighted Average Remaining Maturity	23 days
Derivative Maturity Over Two And Within Three Years From Balance Sheet Date [Member] \| Interest Rate Cap [Member] \| Long [Member]
Derivative [Line Items]
Notional	$ 1,700,000,000
Derivative, Average Cap Interest Rate	1.25%
Weighted Average Variable Interest Rate	2.364%
Weighted Average Remaining Maturity	1 year 6 months 14 days