Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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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

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

+ References

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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- Definition

Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Secured Debt Arrangements, Net - Weighted Average Maturities and Interest Rates of Borrowings (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2018 GBP (£)	Dec. 31, 2017 GBP (£)
Debt Instrument [Line Items]
Borrowings outstanding	$ 1,960,874,000	$ 1,330,847,000
less: deferred financing costs	(20,307,000)	(14,348,000)
Line of Credit [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings	2,682,937,000	2,290,139,000
Borrowings outstanding	1,960,874,000	1,330,847,000
less: deferred financing costs	$ (20,307,000)	$ (14,348,000)
Line of Credit [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted Average Rate	2.27%	2.37%
Line of Credit [Member] \| GBP London Interbank Offered Rate (LIBOR) [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted Average Rate	2.30%	2.60%
Line of Credit [Member] \| JP Morgan Facility [Member] \| General Facility [Member]
Debt Instrument [Line Items]
Line of credit, amount outstanding	$ 1,300,000,000
Line of Credit [Member] \| JP Morgan Facility [Member] \| Asset Specific Financing [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings	132,000,000
Line of credit, amount outstanding	$ 132,000,000
Line of Credit [Member] \| JP Morgan Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted Average Rate	2.26%	2.30%
Line of Credit [Member] \| JP Morgan Facility [Member] \| GBP London Interbank Offered Rate (LIBOR) [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted Average Rate	2.33%
Line of Credit [Member] \| JP Morgan Chase, DB Repurchase Facility, Goldman Sachs And Credit Suisse Facility [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings	$ 2,682,937,000	$ 2,290,139,000
Borrowings outstanding	1,981,181,000	$ 1,345,195,000
Line of Credit [Member] \| Deutsche Bank Repurchase Facility [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings	800,000,000
Borrowings outstanding	625,400,000		£ 118,300,000
Line of Credit [Member] \| Deutsche Bank Repurchase Facility [Member] \| General Facility [Member]
Debt Instrument [Line Items]
Line of credit, amount outstanding	800,000,000
Line of Credit [Member] \| Deutsche Bank Repurchase Facility [Member] \| Asset Specific Financing [Member]
Debt Instrument [Line Items]
Line of credit, amount outstanding	$ 55,000,000
Line of Credit [Member] \| Deutsche Bank Repurchase Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted Average Rate	2.25%	2.56%
Line of Credit [Member] \| Deutsche Bank Repurchase Facility [Member] \| GBP London Interbank Offered Rate (LIBOR) [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted Average Rate	2.52%	2.60%
Line of Credit [Member] \| Goldman Facility [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings	$ 300,000,000	$ 331,130,000
Borrowings outstanding	$ 209,014,000	$ 81,380,000
Line of Credit [Member] \| Goldman Facility [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted Average Rate	2.40%	2.73%
Line of Credit [Member] \| Credit Suisse Facility [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings	$ 145,937,000
Borrowings outstanding	$ 145,937,000		110,500,000
Line of Credit [Member] \| Credit Suisse Facility [Member] \| GBP London Interbank Offered Rate (LIBOR) [Member] \| Weighted Average [Member]
Debt Instrument [Line Items]
Weighted Average Rate	2.05%
USD \| Line of Credit [Member] \| JP Morgan Facility [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings	$ 1,331,780,000	$ 1,393,000,000
Borrowings outstanding	950,634,000	944,529,000
USD \| Line of Credit [Member] \| Deutsche Bank Repurchase Facility [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings	698,824,000	472,090,000
Borrowings outstanding	469,200,000	$ 225,367,000
GBP \| Line of Credit [Member] \| JP Morgan Facility [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings	50,220,000
Borrowings outstanding	$ 50,220,000
GBP \| Line of Credit [Member] \| Deutsche Bank Repurchase Facility [Member]
Debt Instrument [Line Items]
Maximum Amount of Borrowings \| £			156,176,000	£ 93,919,000
Borrowings outstanding \| £			£ 156,176,000	£ 93,919,000