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

The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.

+ References

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

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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5579245-113959

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- Definition

Amount of net gain (loss) recognized in earnings when a hedged firm commitment no longer qualifies as a fair value hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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Derivatives and Hedging Instruments - Narrative (Details)	9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 AUD instrument	Sep. 30, 2017 USD ($) instrument	Sep. 30, 2017 GBP (£) instrument
Cash Flow Hedging
Derivative [Line Items]
Number of instruments held \| instrument			2	2	2
Forward contracts
Derivative [Line Items]
Net derivative (loss) included in OCI expected to be reclassified into earnings	$ 1,800,000
Gains or losses were reclassified from OCI into earnings	$ 0	$ 0
Forward contracts \| Derivatives designated as hedging instruments
Derivative [Line Items]
Derivative instrument, notional amount				$ 16,800,000
Interest rate swap agreements \| Cash Flow Hedging
Derivative [Line Items]
Derivative instrument, notional amount			AUD 30,000,000	23,500,000
Interest rate cap contracts
Derivative [Line Items]
Derivative instrument, notional amount				$ 348,300,000	£ 260,000,000.0