Fair Value Inputs, Fluctuation in Cost to Collect and Discount Rate

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- Definition

Amount of increase (decrease) in fair value from changes in the assumptions or model used to calculate the fair value of a contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

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- Definition

Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
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- Definition

Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock.

+ References

No definition available.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the issuer or the holder.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 946
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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
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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

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
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- Definition

Fair value portion of receivables, including, but not limited to, trade account receivables, note receivables, and loan receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Topic 944
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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.

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Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value inputs, fluctuation in cost to collect and discount rate		1.00%
Convertible senior notes, carrying value	$ 548,500	$ 548,500	$ 448,500
Senior secured notes, carrying value	327,058	327,058	11,320
Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible senior notes, carrying value	513,300	513,300	416,500
Senior Notes \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value estimate of convertible senior notes incorporates quoted market prices	619,900	619,900	431,700
Secured Debt \| Cabot senior secured notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior secured notes, carrying value	1,200,000	1,200,000	1,300,000
Secured Debt \| Level 2 \| Cabot senior secured notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of senior notes	1,300,000	1,300,000	1,300,000
United States
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Increase or decrease of the fair value (100 basis points)		53,800
Europe
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Increase or decrease of the fair value (100 basis points)		71,300
Fair Value \| Certain Loans Acquired in Transfer Not Accounted for as Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of investment receivable portfolios	2,860,500	2,860,500	2,446,600
Carrying Value \| Certain Loans Acquired in Transfer Not Accounted for as Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of investment receivable portfolios	2,728,800	2,728,800	2,382,800
Contingent Consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Issuance (reversal) of contingent consideration in connection with acquisition	10,500
Contingent consideration	10,382	$ 10,382	$ 2,531	$ 10,403
Contingent Consideration \| General and administrative expenses
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Issuance (reversal) of contingent consideration in connection with acquisition	$ (2,800)