Prosper Funding 10-Q 14 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 04, 2017
Document And Entity Information [Line Items]
Entity Registrant Name	PROSPER MARKETPLACE, INC
Entity Central Index Key	1,416,265
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		69,744,201
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Prosper Funding LLC
Document And Entity Information [Line Items]
Entity Registrant Name	Prosper Funding LLC
Entity Central Index Key	1,542,574
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		0

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Cash and Cash Equivalents	$ 34,667	$ 22,337
Restricted Cash	179,331	163,907
Available for Sale Investments, at Fair Value	7,997	32,769
Accounts Receivable	732	757
Loans Held for Sale, at Fair Value	95	624
Borrower Loans, at Fair Value	312,272	315,627
Property and Equipment, Net	22,068	24,853
Prepaid and Other Assets	9,227	4,606
Servicing Assets	13,489	12,786
Goodwill	36,368	36,368
Intangible Assets, Net	1,862	9,212
Total Assets	618,108	623,846
Liabilities, Convertible Preferred Stock and Stockholders' Deficit
Accounts Payable and Accrued Liabilities	10,508	15,017
Payable to Investors	160,611	142,644
Notes at Fair Value	311,410	316,236
Other Liabilities	12,775	17,173
Convertible Preferred Stock Warrant Liability	70,114	21,711
Total Liabilities	565,418	512,781
Commitments and Contingencies (see Note 17)
Convertible Preferred Stock – $0.01 par value; 407,511,351 shares authorized; 177,388,428 issued and outstanding as of June 30, 2017; and 217,388,425 shares authorized, 177,388,425 issued and outstanding as of December 31, 2016. Aggregate liquidation preference of $325,952 as of June 30, 2017 and December 31, 2016.	275,938	275,938
Stockholders' Deficit
Common Stock ($0.01 par value; 550,000,000 shares authorized, 70,719,747 issued and 69,783,812 outstanding as of June 30, 2017; and 338,222,103 shares authorized, 70,843,044 shares issued and 69,907,109 outstanding as of December 31, 2016)	222	212
Additional Paid-In Capital	131,021	123,988
Less: Treasury Stock	(23,417)	(23,417)
Retained Earnings (Accumulated Deficit)	(331,070)	(265,648)
Accumulated Other Comprehensive Loss	(4)	(8)
Total Stockholders' Equity (Deficit)	(223,248)	(164,873)
Total Liabilities, Convertible Preferred Stock and Stockholders' Deficit	618,108	623,846
Prosper Funding LLC
Assets
Cash and Cash Equivalents	12,384	6,929
Restricted Cash	165,628	147,983
Short Term Investments	1	1,280
Loans Held for Sale, at Fair Value	95	624
Borrower Loans, at Fair Value	312,272	315,627
Property and Equipment, Net	9,312	10,095
Servicing Assets	13,297	12,461
Other Assets	257	186
Total Assets	513,246	495,185
Liabilities, Convertible Preferred Stock and Stockholders' Deficit
Accounts Payable and Accrued Liabilities	631	2,223
Payable to Related Party	4,701	1,899
Payable to Investors	159,999	141,625
Notes at Fair Value	311,410	316,236
Other Liabilities	3,188	1,877
Total Liabilities	479,929	463,860
Stockholders' Deficit
Member's Equity	30,704	30,704
Retained Earnings (Accumulated Deficit)	2,613	621
Total Stockholders' Equity (Deficit)	33,317	31,325
Total Liabilities, Convertible Preferred Stock and Stockholders' Deficit	$ 513,246	$ 495,185

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) $ in Thousands	Feb. 16, 2016	Jun. 30, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	May 31, 2016$ / sharesshares
Statement of Financial Position [Abstract]
Convertible preferred stock, par value (in dollars per share) | $ / shares		$ 0.01	$ 0.01
Convertible preferred stock, shares authorized (in shares)		407,511,351	217,388,425	407,511,351
Convertible preferred stock, shares issued (in shares)		177,388,428	177,388,425
Convertible preferred stock, shares outstanding (in shares)		177,388,428	177,388,425
Convertible preferred stock, aggregate liquidation preference | $		$ 325,952	$ 325,952
Common stock, par value (in dollars per share) | $ / shares		$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)		550,000,000	338,222,103	550,000,000
Common stock, shares issued (in shares)		70,719,747	70,843,044
Common stock, shares outstanding (in shares)		69,783,812	69,907,109
Stock split conversion ratio	5

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Operating Revenues
Transaction Fees, Net	$ 35,423,000	$ 19,276,000	$ 62,291,000	$ 61,100,000
Servicing Fees, Net	6,793,000	7,676,000	12,947,000	14,819,000
Gain (Loss) on Sale of Borrower Loans	3,803,000	(687,000)	3,485,000	3,104,000
Fair Value of Warrants Vested on Sale of Borrower Loans	(16,887,000)	0	(20,194,000)	0
Other Revenue	1,415,000	816,000	2,135,000	3,589,000
Total Operating Revenues	30,547,000	27,081,000	60,664,000	82,612,000
Interest Income
Interest Income on Borrower Loans	12,007,000	11,192,000	23,507,000	21,975,000
Interest Expense on Notes	(11,177,000)	(10,098,000)	(21,855,000)	(19,819,000)
Net Interest Income	830,000	1,094,000	1,652,000	2,156,000
Change in Fair Value of Borrower Loans, Loans Held for Sale and Notes, Net	70,000	(2,000)	(24,000)	(79,000)
Total Net Revenue	31,447,000	28,173,000	62,292,000	84,689,000
Expenses
Origination and Servicing	8,873,000	8,833,000	17,278,000	19,282,000
Sales and Marketing	20,131,000	12,303,000	39,687,000	45,023,000
General and Administrative	18,758,000	28,499,000	39,473,000	59,145,000
Restructuring Charges, Net	647,000	14,061,000	572,000	14,061,000
Other Expenses, Net	1,930,000	0	7,629,000	0
Change in Fair Value of Convertible Preferred Stock Warrants	22,416,000	0	22,817,000	0
Total Expenses	72,755,000	63,696,000	127,456,000	137,511,000
Net Loss Before Taxes	(41,308,000)	(35,523,000)	(65,164,000)	(52,822,000)
Income Tax Expense	97,000	105,000	262,000	270,000
Net Income (Loss)	$ (41,405,000)	$ (35,628,000)	$ (65,426,000)	$ (53,092,000)
Net Loss Per Share – Basic and Diluted (in dollars per share)	$ (0.59)	$ (0.56)	$ (0.94)	$ (0.86)
Weighted-Average Shares - Basic and Diluted (in shares)	69,691,841	63,270,058	69,436,365	61,813,773
Prosper Funding LLC
Operating Revenues
Administration Fee Revenue - Related Party	$ 27,309,000	$ 6,930,000	$ 42,463,000	$ 22,348,000
Servicing Fees, Net	6,520,000	7,589,000	12,401,000	14,623,000
Gain (Loss) on Sale of Borrower Loans	(13,084,000)	(687,000)	(16,709,000)	3,104,000
Other Revenue	34,000	26,000	64,000	417,000
Total Operating Revenues	20,779,000	13,858,000	38,219,000	40,492,000
Interest Income
Interest Income on Borrower Loans	12,007,000	10,988,000	23,507,000	21,496,000
Interest Expense on Notes	(11,177,000)	(10,098,000)	(21,855,000)	(19,819,000)
Net Interest Income	830,000	890,000	1,652,000	1,677,000
Change in Fair Value of Borrower Loans, Loans Held for Sale and Notes, Net	70,000	(2,000)	(24,000)	(79,000)
Total Net Revenue	21,679,000	14,746,000	39,847,000	42,090,000
Expenses
Administration Fee - Related Party	18,466,000	15,652,000	34,282,000	36,258,000
Servicing	1,524,000	1,536,000	3,255,000	2,767,000
General and Administrative	145,000	380,000	318,000	737,000
Total Expenses	20,135,000	17,568,000	37,855,000	39,762,000
Income Tax Expense			0	0
Net Income (Loss)	$ 1,544,000	$ (2,822,000)	$ 1,992,000	$ 2,328,000

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Operations (Unaudited) (Parenthetical)	Feb. 16, 2016
Income Statement [Abstract]
Stock split conversion ratio	5

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Other Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net Loss	$ (41,405)	$ (35,628)	$ (65,426)	$ (53,092)
Other Comprehensive Income, Before Tax
Change in Net Unrealized Gain on Available for Sale Investments, at Fair Value	(1)	25	16	215
Realized (Gain) Loss on Sale of Available for Sale Investments, at Fair Value	0	6	(12)	6
Other Comprehensive Income, Before Tax	(1)	31	4	221
Income tax effect	0	0	0	0
Other Comprehensive Income, Net of Tax	(1)	31	4	221
Comprehensive Loss	$ (41,406)	$ (35,597)	$ (65,422)	$ (52,871)

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from Operating Activities:
Net Loss	$ (65,426)	$ (53,092)
Adjustments to Reconcile Net Loss to Net Cash Used in Operating Activities:
Change in Fair Value of Borrower Loans, Loans Held for Sale and Notes	24	79
Depreciation and Amortization	6,270	6,430
Gain on Sales of Borrower Loans	(6,532)	(5,690)
Change in Fair Value of Servicing Rights	5,742	5,647
Stock-Based Compensation Expense	6,812	11,510
Restructuring Liability	412	8,492
Fair Value of Warrants Vested	21,677	0
Change in Fair Value of Warrants	22,817	0
Impairment Losses on Assets Held for Sale	6,319	0
Other, Net	199	227
Changes in Operating Assets and Liabilities:
Purchase of Loans Held for Sale at Fair Value	(1,245,826)	(1,358,011)
Proceeds from Sales and Principal Payments of Loans Held for Sale at Fair Value	1,246,358	1,353,338
Restricted Cash Except for those Related to Investing Activities	(18,329)	20,621
Accounts Receivable	25	1,564
Prepaid and Other Assets	(4,637)	(84)
Accounts Payable and Accrued Liabilities	(3,696)	(4,995)
Payable to Investors	17,967	(21,631)
Other Liabilities	(1,774)	(7,690)
Net Cash Used in Operating Activities	(11,598)	(43,285)
Cash Flows from Investing Activities:
Purchase of Borrower Loans Held at Fair Value	(106,940)	(109,215)
Principal Payments of Borrower Loans Held at Fair Value	99,482	83,514
Purchases of Property and Equipment	(2,485)	(8,600)
Maturities of Short Term Investments	1,280	1,278
Purchases of Short Term Investments	(1,263)	(1,277)
Purchases of Available for Sale Investments, at Fair Value	0	(11,725)
Proceeds from Sale of Available for Sale Investments	16,163	9,193
Maturities of Available for Sale Investments	8,600	20,064
Changes in Restricted Cash Related to Investing Activities	2,905	(2,614)
Net Cash Provided by (Used in) Investing Activities	17,742	(19,382)
Cash Flows from Financing Activities:
Proceeds from Issuance of Notes Held at Fair Value	106,506	109,147
Payments of Notes Held at Fair Value	(100,274)	(84,200)
Proceeds from Exercise of Warrants and Stock Options including Early Exercise, and Issuance of Restricted Stock	18	464
Repurchase of Common Stock and Restricted Stock	(64)	(46)
Net Cash Provided by Financing Activities	6,186	25,196
Net Increase (Decrease) in Cash and Cash Equivalents	12,330	(37,471)
Cash and Cash Equivalents at Beginning of the Period	22,337	66,295
Cash and Cash Equivalents at End of the Period	34,667	28,824
Supplemental Disclosure of Cash Flow Information:
Cash Paid for Interest	22,121	19,787
Non-Cash Investing Activity- Accrual for Property and Equipment, Net	169	346
Prosper Funding LLC
Cash flows from Operating Activities:
Net Loss	1,992	2,328
Adjustments to Reconcile Net Loss to Net Cash Used in Operating Activities:
Change in Fair Value of Borrower Loans, Loans Held for Sale and Notes	24	79
Other Non-Cash Changes in Borrower Loans, Loans Held for Sale and Notes	(272)	39
Depreciation and Amortization	2,637	1,864
Gain on Sales of Borrower Loans	(6,532)	(5,690)
Change in Fair Value of Servicing Rights	5,609	5,387
Changes in Operating Assets and Liabilities:
Purchase of Loans Held for Sale at Fair Value	(1,245,826)	(1,358,011)
Proceeds from Sales and Principal Payments of Loans Held for Sale at Fair Value	1,246,358	1,353,338
Restricted Cash Except for those Related to Investing Activities	(18,701)	21,080
Other Assets	(71)	11
Accounts Payable and Accrued Liabilities	(1,592)	(755)
Payable to Investors	18,374	(22,051)
Net Related Party Receivable/Payable	3,807	2,077
Other Liabilities	1,398	184
Net Cash Used in Operating Activities	7,205	(120)
Cash Flows from Investing Activities:
Purchase of Borrower Loans Held at Fair Value	(106,940)	(109,215)
Principal Payments of Borrower Loans Held at Fair Value	99,482	83,514
Purchases of Property and Equipment	(2,859)	(4,163)
Maturities of Short Term Investments	1,280	1,277
Purchases of Short Term Investments	(1)	(1,279)
Changes in Restricted Cash Related to Investing Activities	1,056	(3,076)
Net Cash Provided by (Used in) Investing Activities	(7,982)	(32,942)
Cash Flows from Financing Activities:
Proceeds from Issuance of Notes Held at Fair Value	106,506	109,147
Payments of Notes Held at Fair Value	(100,274)	(84,200)
Net Cash Provided by Financing Activities	6,232	24,947
Net Increase (Decrease) in Cash and Cash Equivalents	5,455	(8,115)
Cash and Cash Equivalents at Beginning of the Period	6,929	15,026
Cash and Cash Equivalents at End of the Period	12,384	6,911
Supplemental Disclosure of Cash Flow Information:
Cash Paid for Interest	22,121	19,787
Non-Cash Investing Activity- Accrual for Property and Equipment, Net	$ 601	$ 572

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Basis of Presentation	Basis of Presentation Prosper Marketplace, Inc. (“PMI”) was incorporated in the state of Delaware on March 22, 2005. Except as the context requires otherwise, as used in these notes to the condensed consolidated financial statements of Prosper Marketplace, Inc., “Prosper,” “we,” “us,” and “our” refer to PMI and its wholly-owned subsidiaries, on a consolidated basis. The unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“US GAAP”) and disclosure requirements for interim financial information and the requirements of Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements. The unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2016 . The balance sheet at December 31, 2016 has been derived from the audited financial statements at that date. Management believes these unaudited interim condensed consolidated financial statements reflect all adjustments, consisting of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. The preparation of Prosper’s condensed consolidated financial statements and related disclosures in conformity with GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in Prosper’s financial statements and accompanying notes. Management bases its estimates on historical experience and on various other factors it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of certain assets and liabilities. These judgments, estimates and assumptions are inherently subjective in nature and actual results may differ from these estimates and assumptions. The accompanying interim condensed consolidated financial statements include the accounts of PMI and its wholly-owned subsidiaries. All intercompany balances have been eliminated in consolidation.
Prosper Funding LLC
Entity Information [Line Items]
Basis of Presentation	Basis of Presentation Prosper Funding LLC (“PFL”) was formed in the state of Delaware on February 17, 2012 as a limited liability company with the sole equity member being Prosper Marketplace, Inc. (“PMI”, "Parent"). Except as the context otherwise requires, as used in these Notes to the condensed consolidated financial statements of Prosper Funding LLC, “Prosper Funding,” “we,” “us,” and “our” refers to PFL and its wholly owned subsidiaries, Prosper Asset Holdings LLC (“PAH”), a Delaware limited liability company, and Prosper Depositor LLC, a Delaware limited liability company, on a consolidated basis. The unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“US GAAP”) and disclosure requirements for interim financial information and the requirements of Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements. The unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2016 . The balance sheet at December 31, 2016 has been derived from the audited financial statements at that date. Management believes these unaudited interim condensed consolidated financial statements reflect all adjustments, consisting of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. Prosper Funding did no t have any items of other comprehensive income (loss) during any of the periods presented in the condensed consolidated financial statements as of and for the six months ended June 30, 2017 and June 30, 2016 . The preparation of Prosper Funding's condensed consolidated financial statements and related disclosures in conformity with GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in its condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on various other factors it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of certain assets and liabilities. These judgments, estimates and assumptions are inherently subjective in nature and actual results may differ from these estimates and assumptions, and the differences could be material.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Prosper’s significant accounting policies are included in Note 2 – Summary of Significant Accounting Policies in Prosper’s Annual Report on Form 10-K for the year ended December 31, 2016 . There have been no changes to these accounting policies during the first six months of 2017 . Fair Value Measurements Financial instruments consist principally of Cash and Cash Equivalents, Restricted Cash, Available for Sale Investments at Fair Value, Borrower Loans, Loans Held for Sale, Accounts Receivable, Accounts Payable and Accrued Liabilities, Payable to Investors, Convertible Preferred Stock Warrant Liability and Notes. The estimated fair values of Cash and Cash Equivalents, Restricted Cash, Accounts Receivable, Accounts Payable and Accrued Liabilities, and Payable to Investors approximate their carrying values because of their short term nature. Borrower Loans, Loans Held for Sale and Notes Through the Note Channel, Prosper purchases Borrower Loans from WebBank then issues Notes, and holds the Borrower Loans until maturity. The obligation to repay a series of Notes issued through the Note Channel is dependent upon the repayment of the associated Borrower Loan. Borrower Loans funded and Notes issued through the Note Channel are carried on Prosper’s condensed consolidated balance sheets as assets and liabilities, respectively. We choose to measure certain financial instruments and certain other items at fair value on an instrument-by-instrument basis with unrealized gains and losses on items for which the fair value option has been elected reported in earnings. Management believes that the fair value option is more meaningful for the readers of the financial statements and it allows both the Borrower Loans and Notes to be valued using the same methodology. The fair value election, with respect to an item, may not be revoked once an election is made. Prosper estimates the fair value of such Borrower Loans and Notes using discounted cash flow methodologies that take into account expected prepayments, losses, recoveries and default rates. The Borrower Loans are not derecognized when a corresponding Note is issued as Prosper maintains the ability to sell the Borrower Loans without the approval of the holders of the corresponding Notes. Assets Held for Sale: Prosper classifies assets as held for sale when management approves and commits to a formal plan of sale with the expectation the sale will be completed within one year. The net assets held for sale are then recorded at the lower of their current carrying value or the fair market value, less costs to sell. Recent Accounting Pronouncements In May 2014, as part of its ongoing efforts to assist in the convergence of US GAAP and International Financial Reporting Standards (“IFRS”), the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “ Revenue from Contracts with Customers .” The new guidance sets forth a new five-step revenue recognition model which replaces the prior revenue recognition guidance in its entirety and is intended to eliminate numerous industry-specific pieces of revenue recognition guidance that have historically existed in U.S. GAAP. The underlying principle of the new standard is that a business or other organization will recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects what it expects in exchange for the goods or services. The standard also requires more detailed disclosures and provides additional guidance for transactions that were not addressed completely in the prior accounting guidance. The standard will be effective for Prosper in the first quarter of fiscal 2018. In August 2015, the FASB issued ASU No. 2015-14, which amended the standard to provide a one-year deferral of the effective date, as well as providing the option to early adopt the standard on the original effective date. Prosper intends to adopt the guidance for Prosper's fiscal year ending December 31, 2018. The guidance can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Prosper expects to adopt this ASU on a modified retrospective basis in the first quarter of fiscal 2018. Our preliminary results indicate that transaction fees are included in the scope of the new guidance, while servicing fees and gain or loss on the sale of loans remain within the scope of ASC topic 860, Transfers and Servicing. While we anticipate some changes to revenue recognition for certain customer contracts, Prosper does not currently believe that this ASU will have a material effect on our Consolidated Financial Statements. In January 2016, the FASB issued ASU 2016-1, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities" , which addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. This guidance will be effective for us in the first quarter of our fiscal year 2019, and early adoption is not permitted. Prosper is currently evaluating the impact that this guidance will have on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , which requires an entity to recognize assets and liabilities arising from a lease for both financing and operating leases, along with additional qualitative and quantitative disclosures. This guidance will be effective for us in the first quarter of our fiscal year 2019, and early adoption is permitted. Prosper is currently evaluating the impact that this guidance will have on its consolidated financial statements, however we do expect that this guidance will have a material impact on Prosper's consolidated financial statements. As of June 30, 2017 Prosper has a total of $41.4 million in non-cancelable operating lease commitments. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” The standard provides guidance for eight targeted changes with respect to how cash receipts and cash payments are classified in the statements of cash flows, with the objective of reducing diversity in practice. This guidance will be effective for Prosper in the first quarter of our fiscal year 2018, and early adoption is permitted. Prosper is currently evaluating the impacts the adoption of this accounting standard will have on Prosper's consolidated financial statements. In October 2016, the FASB issued ASU No. 2016-16, " Income Taxes (Topic 740): Intra-Entity Transfers Other than Inventory (ASU 2016-16)" , which requires companies to recognize the income-tax consequences of an intra-entity transfer of an asset other than inventory. This guidance will be effective for us in the first quarter of 2018, with the option to adopt it in the first quarter of 2017. Prosper is currently evaluating the impact that this guidance will have on its consolidated financial statements, however we do not believe the standard to have a material impact on our consolidated financial statements. In November 2016, the FASB issued ASU 2016-18, " Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18)" , which requires companies to include amounts generally described as restricted cash and restricted cash equivalents in cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance will be effective for us in the first quarter of 2018 and early adoption is permitted. Prosper is currently evaluating the effect that this guidance will have on our consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment ". The standard eliminates Step 2 from the goodwill impairment test, which requires a hypothetical purchase price allocation. Prosper will continue to have the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. The standard is effective for interim and annual periods beginning after December 15, 2019 and early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The standard should be applied on a prospective basis. Prosper is currently evaluating the impact of this accounting standard update on its consolidated financial statements.
Prosper Funding LLC
Entity Information [Line Items]
Summary of Significant Accounting Policies	Significant Accounting Policies Prosper Funding's significant accounting policies are included in Note 2 – Summary of Significant Accounting Policies in Prosper Funding’s Annual Report on Form 10-K for the year ended December 31, 2016 . There have been no changes to these accounting policies during the first six months of 2017 . Fair Value Measurements Financial instruments consist principally of Cash and Cash Equivalents, Restricted Cash, Short Term Investments, Borrower Loans, Loans Held for Sale, Accounts Receivable, Accounts Payable and Accrued Liabilities, Payable to Investors and Notes. The estimated fair values of Cash and Cash Equivalents, Restricted Cash, Accounts Receivable, Accounts Payable and Accrued Liabilities, and Payable to Investors approximate their carrying values because of their short term nature. Borrower Loans, Loans Held for Sale and Notes Through the Note Channel, Prosper Funding purchases Borrower Loans from WebBank then issues Notes, and holds the Borrower Loans until maturity. The obligation to repay a series of Notes funded through the Note Channel is dependent upon the repayment of the associated Borrower Loan. Borrower Loans and Notes funded through the Note Channel are carried on Prosper Funding’s consolidated balance sheets as assets and liabilities, respectively. We choose to measure certain financial instruments and certain other items at fair value on an instrument-by-instrument basis with unrealized gains and losses on items for which the fair value option has been elected reported in earnings. Management believes that the fair value option is more meaningful for the readers of the financial statements and it allows both the Borrower Loans and Notes to be valued using the same methodology. The fair value election, with respect to an item, may not be revoked once an election is made. Prosper Funding estimates the fair value of such Borrower Loans and Notes using discounted cash flow methodologies that take into account expected prepayments, losses, recoveries and default rates. The Borrower Loans are not derecognized when a corresponding Note is issued as Prosper Funding maintains the ability to sell the Borrower Loans without the approval of the holders of the corresponding Notes. Recent Accounting Pronouncements In May 2014, as part of its ongoing efforts to assist in the convergence of US GAAP and International Financial Reporting Standards (“IFRS”), the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers.” The new guidance sets forth a new five-step revenue recognition model which replaces the prior revenue recognition guidance in its entirety and is intended to eliminate numerous industry-specific pieces of revenue recognition guidance that have historically existed in U.S. GAAP. The underlying principle of the new standard is that a business or other organization will recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects what it expects in exchange for the goods or services. The standard also requires more detailed disclosures and provides additional guidance for transactions that were not addressed completely in the prior accounting guidance. The standard will be effective for Prosper Funding in the first quarter of fiscal 2018. In August 2015, the FASB issued ASU No. 2015-14, which amended the standard to provide a one-year deferral of the effective date, as well as providing the option to early adopt the standard on the original effective date. The guidance can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Prosper Funding expects to adopt this ASU on a modified retrospective basis in the first quarter of fiscal 2018. Our evaluation of this ASU is ongoing and not complete. The FASB has issued and may issue in the future, interpretative guidance, which may cause our evaluation to change. Our preliminary results indicate that administration fees are included in the scope of the new guidance, while servicing fees and gain or loss on the sale of loans remain within the scope of ASC topic 860, Transfers and Servicing. Prosper Funding does not currently believe that this ASU will have a material effect on our Consolidated Financial Statements. In January 2016, the FASB issued ASU 2016-1, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities" , which addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. This guidance will be effective for us in the first quarter of our fiscal year 2019, and early adoption is not permitted. Prosper Funding is currently evaluating the impact that this guidance will have on our consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” The standard provides guidance for eight targeted changes with respect to how cash receipts and cash payments are classified in the statements of cash flows, with the objective of reducing diversity in practice. This guidance will be effective for Prosper Funding in the first quarter of our fiscal year 2018, and early adoption is permitted. Prosper Funding is currently evaluating the impacts the adoption of this accounting standard will have on the Prosper Funding's cash flows. In November 2016, the FASB issued ASU 2016-18, "Statement of Cash Flows (Topic 230): Restricted Cash (ASU2016-18)", which requires companies to include amounts generally described as restricted cash and restricted cash equivalents in cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance will be effective for us in the first quarter of 2018 and early adoption is permitted. Prosper Funding is currently evaluating the effect that this guidance will have on our consolidated financial statements and related disclosures.

Property and Equipment, Net

Property and Equipment, Net	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Property and Equipment, Net	Property and Equipment, Net Property and equipment consist of the following (in thousands): June 30, December 31, Property and equipment: Computer equipment $ 14,370 $ 14,107 Internal-use software and website development costs 18,603 16,750 Office equipment and furniture 3,010 3,010 Leasehold improvements 7,038 7,038 Assets not yet placed in service 1,453 1,222 Property and equipment 44,474 42,127 Less accumulated depreciation and amortization (22,406 ) (17,274 ) Total property and equipment, net $ 22,068 $ 24,853 Depreciation and amortization expense for property and equipment for the three months ended June 30, 2017 and 2016 was $2.7 million and $2.5 million , respectively. Depreciation and amortization expense for property and equipment for the six months ended June 30, 2017 and 2016 was $5.2 million and $4.5 million respectively. Prosper capitalized internal-use software and website development costs in the amount of $1.0 million and $1.8 million for the three months ended June 30, 2017 and 2016 , respectively. Prosper capitalized internal-use software and website development costs in the amount of $2.1 million and $3.6 million for the six months ended June 30, 2017 and 2016 , respectively.
Prosper Funding LLC
Entity Information [Line Items]
Property and Equipment, Net	Property and Equipment Property and equipment consist of the following (in thousands): June 30, December 31, Property and equipment: Internal-use software and web site development costs $ 18,603 $ 16,749 Less accumulated depreciation and amortization (9,291 ) (6,654 ) Total property and equipment, net $ 9,312 $ 10,095 Depreciation expense for the three months ended June 30, 2017 and 2016 was $1.4 million and $1.0 million , respectively. Depreciation expense for the six months ended June 30, 2017 and 2016 was $2.6 million and $1.9 million , respectively.

Borrower Loans, Loans Held for

Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value	Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value The aggregate principal balances outstanding and fair values of Borrower Loans, Loans Held for Sale and Notes as of June 30, 2017 and December 31, 2016 , are presented in the following table (in thousands): Borrower Loans Notes Loans Held for Sale June 30, December 31, June 30, December 31, June 30, December 31, Aggregate principal balance outstanding $ 316,378 $ 319,143 $ (319,072 ) $ (323,358 ) $ 106 $ 641 Fair value adjustments (4,106 ) (3,516 ) 7,662 7,122 (11 ) (17 ) Fair value $ 312,272 $ 315,627 $ (311,410 ) $ (316,236 ) $ 95 $ 624 At June 30, 2017 , outstanding Borrower Loans had original terms to maturity of either 36 or 60 months ; had monthly payments with fixed interest rates ranging from 5.32% to 33.04% and had various maturity dates through June 2022 . At December 31, 2016 , outstanding Borrower Loans had original maturities of either 36 or 60 months ; had monthly payments with fixed interest rates ranging from 5.32% to 33.04% and had various maturity dates through December 2021 . Approximately $1.2 million and $2.0 million represents the loss that is attributable to changes in the instrument specific credit risks related to Borrower Loans that were recorded in the change in fair value during the six months ending June 30, 2017 and June 30, 2016 , respectively. As of June 30, 2017 , Borrower Loans that were 90 days or more delinquent had an aggregate principal amount of $2.6 million and a fair value of $0.9 million . As of December 31, 2016 , Borrower Loans that were 90 days or more delinquent had an aggregate principal amount of $3.2 million and a fair value of $1.0 million . Prosper places loans on non-accrual status when they are over 120 days past due. As of June 30, 2017 and December 31, 2016 , Borrower Loans in non-accrual status had a fair value of $0.2 million and $0.5 million , respectively.
Prosper Funding LLC
Entity Information [Line Items]
Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value	Borrower Loans, Loans Held For Sale and Notes Held at Fair Value The aggregate principal balances outstanding and fair values of Borrower Loans, Loans Held for Sale and Notes as of June 30, 2017 and December 31, 2016 , are presented in the following table (in thousands): Borrower Loans Notes Loans Held for Sale June 30, 2017 December 31, 2016 June 30, 2017 December 31, 2016 June 30, 2017 December 31, 2016 Aggregate principal balance outstanding $ 316,378 $ 319,143 $ (319,072 ) $ (323,358 ) $ 106 $ 641 Fair value adjustments (4,106 ) (3,516 ) 7,662 7,122 (11 ) (17 ) Fair value $ 312,272 $ 315,627 $ (311,410 ) $ (316,236 ) $ 95 $ 624 At June 30, 2017 , outstanding Borrower Loans had original terms to maturity of either 36 or 60 months ; had monthly payments with fixed interest rates ranging from 5.32% to 33.04% and had various maturity dates through June 2022 . At December 31, 2016 , outstanding Borrower Loans had original maturities of either 36 or 60 months ; had monthly payments with fixed interest rates ranging from 5.32% to 33.04% and had various maturity dates through December 2021 . Approximately $1.2 million represents the loss that is attributable to changes in the instrument specific credit risks related to Borrower Loans that were recorded in the change in fair value during the six months ended June 30, 2017 . As of June 30, 2017 , Borrower Loans that were 90 days or more delinquent had an aggregate principal amount of $2.6 million and a fair value of $0.9 million . As of December 31, 2016 , Borrower Loans that were 90 days or more delinquent had an aggregate principal amount of $3.2 million and a fair value of $1.0 million . Prosper Funding places loans on non-accrual status when they are over 120 days past due. As of June 30, 2017 and December 31, 2016 , Borrower Loans in non-accrual status had a fair value of $0.2 million and $0.5 million , respectively.

Loan Servicing Assets and Liabi

Loan Servicing Assets and Liabilities	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Loan Servicing Assets and Liabilities	Loan Servicing Assets and Liabilities Prosper accounts for servicing assets and liabilities at their estimated fair values with changes in fair values recorded in servicing fees. The initial asset or liability is recognized when Prosper sells Borrower Loans to unrelated third-party buyers through the Whole Loan Channel and the servicing rights are retained. The servicing assets and liabilities are measured at fair value throughout the servicing period. The total gains losses recognized on the sale of such Borrower Loans for the three months ended June 30, 2017 were a gain of $3.8 million and a loss of $16.9 million from the Fair Value of Warrants Vested on the Sale of Borrower Loans to the Consortium after the closing of the Consortium transaction. The total gains and losses recognized on the sale of such Borrower Loans for the six months ended June 30, 2017 were a gain of $3.5 million and a loss of $20.2 million from the Fair Value of Warrants Vested on the Sale of Borrower Loans to the Consortium after the closing of the Consortium transaction. Total losses recognized on the sale of such Borrower Loans were $0.7 million during the three months ended June 30, 2016. Total gains recognized on the sale of such Borrower Loans were $3.1 million during the six months ended June 30, 2016. As of June 30, 2017 , Borrower Loans that were sold but for which Prosper retained servicing rights had a total outstanding principal balance of $3.6 billion , original terms of either 36 or 60 months and had monthly payments with fixed interest rates ranging from 5.32% to 35.52% and various maturity dates through June 2022 . At December 31, 2016 , Borrower Loans that were sold but for which Prosper retained servicing rights had a total outstanding principal balance of $3.5 billion , original terms of either 36 or 60 months and had monthly payments with fixed interest rates ranging from 5.32% to 35.52% and various maturity dates through December 2021 . $9.4 million and $10.4 million of contractually specified servicing fees and ancillary fees are included on our condensed consolidated statements of operations in Servicing Fees, Net for the three months ended June 30, 2017 and 2016 , respectively. $18.2 million and $20.0 million of contractually specified servicing fees and ancillary fees are included on our condensed consolidated statements of operations in Servicing Fees, Net for the six months ended June 30, 2017 and 2016 , respectively. Fair value Valuation method – Prosper uses a discounted cash flow valuation methodology generally consisting of developing an estimate of future cash flows that are expected to occur over the life of a financial instrument and then discounting those cash flows at a rate of return that results in the fair value amount. Significant unobservable inputs presented in the table within Note 7 below are those that Prosper considers significant to the estimated fair values of the Level 3 servicing assets and liabilities. The following is a description of the significant unobservable inputs provided in the table. Market servicing rate – Prosper estimates adequate market servicing rates that would fairly compensate a substitute servicer should one be required, which includes the profit that would be demanded in the marketplace. This rate is stated as a fixed percentage of outstanding principal balance on a per annum basis. Prosper estimated these market servicing rates based on observable market rates for other loan types in the industry and bids from subservicing providers, adjusted for the unique loan attributes that are present in the specific loans that Prosper sells and services and information from a backup service provider. Discount rate – The discount rate is a rate of return used to discount future expected cash flows to arrive at a present value, which represents the fair value of the loan servicing rights. We used a range of discount rates for the servicing assets and liabilities based on comparable observed valuations of similar assets and publicly available disclosures related to servicing valuations, with comparability adjustments made to account for differences with Prosper’s servicing assets. Default Rate – The default rate presented in Note 7 is an annualized, average estimate considering all Borrower Loan categories (i.e. risk ratings and duration), and represents an aggregate of conditional default rate curves for each credit grade or Borrower Loan category. Each point on a particular Borrower Loan category’s curve represents the percentage of principal expected to default per period based on the term and age of the underlying Borrower Loans. The assumption regarding defaults directly reduces servicing revenues because the amount of servicing revenues received is based on the amount collected each period. Prepayment Rate – The prepayment rate presented in Note 7 is an annualized, average estimate considering all Borrower Loan categories (i.e. risk ratings and duration), and represents an aggregate of conditional prepayment rate curves for each credit grade or Borrower Loan category. Each point on a particular Borrower Loan category’s curve represents the percentage of principal expected to prepay per period based on the term and age of the underlying Borrower Loans. Prepayments reduce servicing revenues as they shorten the period over which we expect to collect fees on the Borrower Loans, which is used to project future servicing revenues.
Prosper Funding LLC
Entity Information [Line Items]
Loan Servicing Assets and Liabilities	Loan Servicing Assets and Liabilities Prosper Funding accounts for servicing assets and liabilities at their estimated fair values with changes in fair values recorded in servicing fees. The initial asset or liability is recognized when Prosper Funding sells Borrower Loans to unrelated third-party buyers through the Whole Loan Channel and the servicing rights are retained. The total losses recognized on the sale of such Borrower Loans were $13.1 million and $0.7 million for the three months ended June 30, 2017 and June 30, 2016 , respectively. The total gains and losses recognized on the sale of such Borrower Loans were a loss of $16.7 million and gain of $3.1 million for the six months ended June 30, 2017 and June 30, 2016 , respectively. At June 30, 2017 , Borrower Loans that were sold, but for which Prosper Funding retained servicing rights, had a total outstanding principal balance of $3.5 billion , original terms of either 36 or 60 months and had monthly payments with fixed interest rates ranging from 5.32% to 35.52% and various maturity dates through June 2022 . At December 31, 2016 , Borrower Loans that were sold, but for which Prosper Funding retained servicing rights, had a total outstanding principal balance of $3.4 billion , original terms of either 36 or 60 months and had monthly payments with fixed interest rates ranging from 5.32% to 35.52% and various maturity dates through December 2021 . $9.2 million and $10.3 million of contractually specified servicing fees and ancillary fees are included on our condensed consolidated statements of operations in Servicing Fees, Net for the three months ended June 30, 2017 and 2016 , respectively. $17.9 million and $19.7 million of contractually specified servicing fees and ancillary fees are included on our condensed consolidated statements of operations in Servicing Fees, Net for the six months ended June 30, 2017 and 2016 , respectively. Fair value Valuation method – Prosper Funding uses a discounted cash flow valuation methodology generally consisting of developing an estimate of future cash flows that are expected to occur over the life of a financial instrument and then discounting those cash flows at a rate of return that results in the fair value amount. Significant unobservable inputs presented in the table within Note 7 below are those that Prosper Funding considers significant to the estimated fair values of the Level 3 servicing assets and liabilities. The following is a description of the significant unobservable inputs provided in the table. Market servicing rate – Prosper Funding estimates adequate market servicing rates that would fairly compensate a substitute servicer should one be required, which includes the profit that would be demanded in the marketplace. This rate is stated as a fixed percentage of outstanding principal balance on a per annum basis. Prosper Funding estimated these market servicing rates based on observable market rates for other loan types in the industry and bids from subservicing providers, adjusted for the unique loan attributes that are present in the specific loans that Prosper Funding sells and services and information from a backup service provider. Discount rate – The discount rate is a rate of return used to discount future expected cash flows to arrive at a present value, which represents the fair value of the loan servicing rights. We used a range of discount rates for the servicing assets and liabilities based on comparable observed valuations of similar assets and publicly available disclosures related to servicing valuations, with comparability adjustments made to account for differences with Prosper Funding’s servicing assets. Default Rate – The default rate presented in Note 7 is an annualized, average estimate considering all Borrower Loan categories (i.e. risk ratings and duration), and represents an aggregate of conditional default rate curves for each credit grade or Borrower Loan category. Each point on a particular Borrower Loan category’s curve represents the percentage of principal expected to default per period based on the term and age of the underlying Borrower Loans. The assumption regarding defaults directly reduces servicing revenues because the amount of servicing revenues received is based on the amount collected each period. Prepayment Rate – The prepayment rate presented in Note 7 is an annualized, average estimate considering all Borrower Loan categories (i.e. risk ratings and duration), and represents an aggregate of conditional prepayment rate curves for each credit grade or Borrower Loan category. Each point on a particular Borrower Loan category’s curve represents the percentage of principal expected to prepay per period based on the term and age of the underlying Borrower Loans. Prepayments reduce servicing revenues as they shorten the period over which we expect to collect fees on the Borrower Loans, which is used to project future servicing revenues.

Available for Sale Investments,

Available for Sale Investments, at Fair Value	6 Months Ended
	Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Available for Sale Investments, at Fair Value	Available for Sale Investments, at Fair Value Available for sale investments are recorded at fair value and unrealized gains and losses are reported, net of taxes, in accumulated other comprehensive income (loss) included in stockholders' equity unless management determines that an investment is other-than-temporarily impaired (OTTI). The amortized cost, gross unrealized gains and losses, and fair value of available for sale investments as of June 30, 2017 and December 31, 2016 , are as follows (in thousands): June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity securities: US Treasury securities 5,501 — (3 ) 5,498 Agency bonds 2,500 — (1 ) 2,499 Total Available for Sale Investments $ 8,001 $ — $ (4 ) $ 7,997 December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity securities: Corporate debt securities $ 21,762 $ 1 $ (10 ) $ 21,753 US Treasury securities 8,516 3 (3 ) 8,516 Agency bonds 2,499 1 — 2,500 Total Available for Sale Investments $ 32,777 $ 5 $ (13 ) $ 32,769 A summary of available for sale investments with unrealized losses as of June 30, 2017 , and December 31, 2016 , aggregated by category and period of continuous unrealized loss, is as follows (in thousands): Less than 12 months 12 months or longer Total June 30, 2017 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed maturity securities: U.S. treasury securities $ 5,498 $ (3 ) $ 5,498 $ (3 ) Agency bonds — — 2,499 (1 ) 2,499 (1 ) Total Investments with Unrealized Losses $ 5,498 $ (3 ) $ 2,499 $ (1 ) $ 7,997 $ (4 ) Less than 12 months 12 months or longer Total December 31, 2016 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed maturity securities: Corporate debt securities $ — $ — $ 14,651 $ (10 ) $ 14,651 $ (10 ) U.S. treasury securities $ — $ — $ 4,499 $ (3 ) $ 4,499 $ (3 ) Total Investments with Unrealized Losses $ — $ — $ 19,150 $ (13 ) $ 19,150 $ (13 ) There were no impairment charges recognized during the six months ended June 30, 2017 . The maturities of available for sale investments at June 30, 2017 and December 31, 2016 are as follows (in thousands): June 30, 2017 Within 1 year After 1 year through 5 years After 5 years to 10 years After 10 years Total US Treasury securities 5,498 5,498 Agency bonds 2,499 2,499 Total Fair Value $ 7,997 $ — $ — $ — $ 7,997 Total Amortized Cost $ 8,001 $ — $ — $ — $ 8,001 December 31, 2016 Within 1 year After 1 year through 5 years After 5 years to 10 years After 10 years Total Corporate debt securities 21,753 — — — 21,753 US Treasury securities 8,516 — — — 8,516 Agency bonds 2,500 — — — 2,500 Total Fair Value $ 32,769 $ — $ — $ — $ 32,769 Total Amortized Cost $ 32,777 $ — $ — $ — $ 32,777 During the six months ended June 30, 2017 , Prosper sold $16.2 million of investments which resulted in a realized gain of $12 thousand .

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities Prosper measures the fair value of assets and liabilities in accordance with its fair value hierarchy which prioritizes information used to measure fair value and the effect of fair value measurements on earnings and provides for enhanced disclosures determined by the level within the hierarchy of information used in the valuation. We apply this framework whenever other standards require (or permit) assets or liabilities to be measured at fair value. Assets and liabilities carried at fair value on the balance sheets are classified among three levels based on the observability of the inputs used to determine fair value: Level 1 — The valuation is based on quoted prices in active markets for identical instruments. Level 2 — The valuation is based on observable inputs such as quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation methodologies for which all significant assumptions are observable in the market. Level 3 — The valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the instrument. Level 3 valuations are typically performed using pricing models, discounted cash flow methodologies, or similar methodologies, which incorporate management’s own estimates of assumptions that market participants would use in pricing the instrument or valuations that require significant management judgment or estimation. Fair values of assets or liabilities are determined based on the fair value hierarchy, which requires an entity to maximize the use of quoted prices and observable inputs and to minimize the use of unobservable inputs when measuring fair value. Various valuation methodologies are utilized, depending on the nature of the financial instrument, including the use of market prices for identical or similar instruments, or discounted cash flow models. When possible, active and observable market data for identical or similar financial instruments are utilized. Alternatively, fair value is determined using assumptions that management believes a market participant would use in pricing the asset or liability. Financial instruments consist principally of Cash and Cash Equivalents, Restricted Cash, Available for Sale Investments, Borrower Loans, Loans Held for Sale, Accounts Receivable, Accounts Payable and Accrued Liabilities, Payable to Investors, Convertible Preferred Stock Warrant and Notes. Servicing Assets and Liabilities are also subject to fair value measurement within the financial statements of Prosper. The estimated fair values of Cash and Cash Equivalents, Restricted Cash, Accounts Receivable, Accounts Payable and Accrued Liabilities, and Payable to Investors approximate their carrying values because of their short term nature. Financial Instruments Recorded at Fair Value The fair value of the Borrower Loans, Loans Held for Sale and Notes are estimated using discounted cash flow methodologies based upon a set of valuation assumptions. The primary cash flow assumptions used to value such Borrower Loans, Loans Held for Sale and Notes include default rates derived from historical performance and discount rates applied to each credit grade based on the perceived credit risk of each credit grade. Investments held at fair value consist of available for sale investments. The available for sale investments consist of corporate debt securities, commercial paper, U.S. treasury securities, agency bonds and short term bond funds. When available, Prosper uses quoted prices in active markets to measure the fair value of securities available for sale. When utilizing market data and bid-ask spreads, Prosper uses the price within the bid-ask spread that best represents fair value. When quoted prices do not exist, Prosper uses prices obtained from independent third-party pricing services to measure the fair value of investment assets. Prosper generally obtains prices from at least two independent pricing sources for assets recorded at fair value. Prosper's primary independent pricing service provides prices based on observable trades and discounted cash flows that incorporate observable information, such as yields for similar types of securities (a benchmark interest rate plus observable spreads) and weighted-average maturity for the same or similar securities. Prosper compares the prices obtained from its primary independent pricing service to the prices obtained from the additional independent pricing services to determine if the price obtained from the primary independent pricing service is reasonable. Prosper does not adjust the prices received from independent third-party pricing services unless such prices are inconsistent with the definition of fair value and result in a material difference in the recorded amounts. The Convertible Preferred Stock Warrant Liability is valued using a Black Scholes-Option pricing model. Refer to Note 12 for further details. The following tables present the fair value hierarchy for assets and liabilities measured at fair value (in thousands): June 30, 2017 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 312,272 $ 312,272 Loans Held for Sale — — 95 95 Available for Sale Investments, at Fair Value — 7,997 — 7,997 Servicing Assets — — 13,489 13,489 Total Assets — 7,997 325,856 333,853 Liabilities: Notes $ — $ — $ 311,410 $ 311,410 Servicing Liabilities — — 111 111 Convertible Preferred Stock Warrant Liability — — 70,114 70,114 Loan Trailing Fee Liability — — 1,655 1,655 Total Liabilities $ — $ — $ 383,290 $ 383,290 December 31, 2016 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 315,627 $ 315,627 Loans Held for Sale — — 624 624 Available for Sale Investments, at Fair Value — 32,769 — 32,769 Servicing Assets — — 12,786 12,786 Total Assets — 32,769 329,037 361,806 Liabilities: Notes $ — $ — $ 316,236 $ 316,236 Servicing Liabilities — — 198 198 Convertible Preferred Stock Warrant Liability — — 21,711 21,711 Loan Trailing Fee Liability — — 665 665 Total Liabilities $ — $ — $ 338,810 $ 338,810 As Prosper’s Borrower Loans, Loans Held for Sale, Notes and loan servicing rights do not trade in an active market with readily observable prices, Prosper uses significant unobservable inputs to measure the fair value of these assets and liabilities. Financial instruments are categorized in the level 3 valuation hierarchy based on the significance of unobservable factors in the overall fair value measurement. These fair value estimates may also include observable, actively quoted components derived from external sources. As a result, the realized and unrealized gains and losses for assets and liabilities within the level 3 category may include changes in fair value that were attributable to both observable and unobservable inputs. Significant Unobservable Inputs The following tables present quantitative information about the significant unobservable inputs used for Prosper’s level 3 fair value measurements at June 30, 2017 and December 31, 2016 : Borrower Loans, Loans Held for Sale and Notes: Range Unobservable Input June 30, 2017 December 31, 2016 Discount rate 4.3% - 15.2% 4.0% - 15.9% Default rate 1.9% - 15.2% 1.7% - 14.9% Servicing Rights Range Unobservable Input June 30, 2017 December 31, 2016 Discount rate 15% - 25% 15% - 25% Default rate 1.6% - 15.7% 1.5% - 15.2% Prepayment rate 14.4% - 26.7% 13.6% - 26.6% Market servicing rate 0.625 % 0.625 % At June 30, 2017 , the discounted cash flow methodology used to estimate the Note fair values used the same projected cash flows as the related Borrower Loans. As demonstrated in the following table, the fair value adjustments for Borrower Loans were largely offset by the fair value adjustments of the Notes due to the borrower payment dependent design of the Notes and because the principal balances of the Borrower Loans approximated the principal balances of the Notes. The following tables present additional information about level 3 Borrower Loans, Loans Held for Sale and Notes measured at fair value on a recurring basis (in thousands): Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at January 1, 2017 $ 315,627 $ (316,236 ) $ 624 $ 15 Purchase of Borrower Loans/Issuance of Notes 106,940 (106,506 ) 1,245,826 1,246,260 Principal repayments (97,492 ) 100,274 (42 ) 2,740 Borrower Loans sold to third parties (1,990 ) — (1,246,316 ) (1,248,306 ) Other changes 9 266 (3 ) 272 Change in fair value (10,822 ) 10,792 6 (24 ) Balance at June 30, 2017 $ 312,272 $ (311,410 ) $ 95 $ 957 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at January 1, 2016 $ 297,273 $ (297,405 ) $ 32 $ (100 ) Purchase of Borrower Loans/Issuance of Notes 109,215 (109,147 ) 1,358,011 1,358,079 Principal repayments (82,376 ) 83,119 (136 ) 607 Borrower Loans sold to third parties (1,138 ) 1,081 (1,353,202 ) (1,353,259 ) Other changes (6 ) (33 ) — (39 ) Change in fair value (12,934 ) 12,855 — (79 ) Balance at June 30, 2016 $ 310,034 $ (309,530 ) $ 4,705 $ 5,209 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at April 1, 2017 $ 317,536 $ (316,944 ) $ 109 $ 701 Purchase of Borrower Loans/Issuance of Notes 50,260 (49,692 ) 721,829 722,397 Principal repayments (48,048 ) 48,695 (14 ) 633 Borrower Loans sold to third parties (869 ) — (721,829 ) (722,698 ) Other changes 10 (156 ) — (146 ) Change in fair value (6,617 ) 6,687 — 70 Balance at June 30, 2017 $ 312,272 $ (311,410 ) $ 95 $ 957 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at April 1, 2016 $ 303,243 $ (302,357 ) $ 30 $ 916 Purchase of Borrower Loans/Issuance of Notes 54,044 (53,873 ) 426,591 426,762 Principal repayments (41,390 ) 41,057 (131 ) (464 ) Borrower Loans sold to third parties (525 ) 499 (421,784 ) (421,810 ) Other changes (2 ) (191 ) — (193 ) Change in fair value (5,336 ) 5,335 (1 ) (2 ) Balance at June 30, 2016 $ 310,034 $ (309,530 ) $ 4,705 $ 5,209 The following tables present additional information about level 3 servicing assets and liabilities measured at fair value on a recurring basis (in thousands): Servicing Assets Servicing Liabilities Fair Value at January 1, 2017 12,786 198 Additions 6,532 — Less: Changes in fair value (5,829 ) (87 ) Fair Value at June 30, 2017 13,489 111 Servicing Assets Servicing Liabilities Fair Value at January 1, 2016 14,363 484 Additions 5,750 9 Less: Changes in fair value (5,816 ) (169 ) Fair Value at June 30, 2016 14,297 324 Servicing Assets Servicing Liabilities Fair Value at April 1, 2017 12,436 147 Additions 3,768 — Less: Changes in fair value (2,715 ) (36 ) Fair Value at June 30, 2017 13,489 111 Servicing Assets Servicing Liabilities Fair Value at April 1, 2016 15,548 398 Additions 1,729 — Less: Changes in fair value (2,980 ) (74 ) Fair Value at June 30, 2016 14,297 324 The following table presents additional information about level 3 Loan Trailing Fee Liability measured at fair value on a recurring basis (in thousands): Balance at January 1, 2017 665 Issuances 1,216 Cash payment of Loan Trailing Fee (351 ) Change in fair value 125 Balance at June 30, 2017 1,655 Significant Recurring Level 3 Fair Value Asset and Liability Input Sensitivity Key economic assumptions and the sensitivity of the current fair value to immediate changes in those assumptions at June 30, 2017 for Borrower Loans, Loans Held for Sale and Notes funded through the Note Channel are presented in the following table (in thousands, except percentages): Borrower Loans and Loans Held for Sale Notes Discount rate assumption: 7.55 % * 7.55 % * Resulting fair value from: 100 basis point increase $ 309,203 $ 308,250 200 basis point increase 306,119 305,170 Resulting fair value from: 100 basis point decrease $ 315,614 $ 314,653 200 basis point decrease 318,948 317,984 Default rate assumption: 12.96 % * 12.96 % * Resulting fair value from: 100 basis point increase $ 308,608 $ 307,645 200 basis point increase 304,984 304,015 Resulting fair value from: 100 basis point decrease $ 316,150 $ 315,200 200 basis point decrease 319,980 319,038 * Represents weighted average assumptions considering all credit grades. The following table presents the estimated impact on Prosper’s estimated fair value of servicing assets and liabilities, calculated using different market servicing rates and different default rates as of June 30, 2017 (in thousands, except percentages). Servicing Assets Servicing Liabilities Market servicing rate assumptions 0.625 % 0.625 % Resulting fair value from: Market servicing rate increase to 0.65% $ 12,613 $ 122 Market servicing rate decrease to 0.60% $ 14,365 $ 100 Weighted average prepayment assumptions 20.09 % 20.09 % Resulting fair value from: Applying a 1.1 multiplier to prepayment rate $ 13,301 $ 109 Applying a 0.9 multiplier to prepayment rate $ 13,678 $ 113 Weighted average default assumptions 12.18 % 12.18 % Resulting fair value from: Applying a 1.1 multiplier to default rate $ 13,301 $ 111 Applying a 0.9 multiplier to default rate $ 13,680 $ 111 These sensitivities are hypothetical and should be evaluated with care. The effect on fair value of a variation in assumptions generally cannot be determined because the relationship of the change in assumptions to the fair value may not be linear. Additionally, the impact of a variation in a particular assumption on the fair value is calculated while holding other assumptions constant. In reality, changes in one factor may lead to changes in other factors, which could impact the above hypothetical effects.
Prosper Funding LLC
Entity Information [Line Items]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities Prosper Funding measures the fair value of assets and liabilities in accordance with its fair value hierarchy which prioritizes information used to measure fair value and the effect of fair value measurements on earnings and provides for enhanced disclosures determined by the level within the hierarchy of information used in the valuation. We apply this framework whenever other standards require (or permit) assets or liabilities to be measured at fair value. Assets and liabilities carried at fair value on the balance sheets are classified among three levels based on the observability of the inputs used to determine fair value: Level 1 — The valuation is based on quoted prices in active markets for identical instruments. Level 2 — The valuation is based on observable inputs such as quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation methodologies for which all significant assumptions are observable in the market. Level 3 — The valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the instrument. Level 3 valuations are typically performed using pricing models, discounted cash flow methodologies, or similar methodologies, which incorporate management’s own estimates of assumptions that market participants would use in pricing the instrument or valuations that require significant management judgment or estimation. Fair values of assets or liabilities are determined based on the fair value hierarchy, which requires an entity to maximize the use of quoted prices and observable inputs and to minimize the use of unobservable inputs when measuring fair value. Various valuation methodologies are utilized, depending on the nature of the financial instrument, including the use of market prices for identical or similar instruments, or discounted cash flow models. When possible, active and observable market data for identical or similar financial instruments are utilized. Alternatively, fair value is determined using assumptions that management believes a market participant would use in pricing the asset or liability. Financial instruments consist principally of cash and cash equivalents, restricted cash, Borrower Loans, accounts payable and accrued liabilities, and Notes. Servicing assets and liabilities are also subject to fair value measurement within the financial statements of Prosper Funding. The estimated fair values of cash and cash equivalents, restricted cash, accounts payable and accrued liabilities approximate their carrying values because of their short term nature. Financial Instruments Recorded at Fair Value The fair value of the Borrower Loans, Loans Held for Sale and Notes are estimated using discounted cash flow methodologies based upon a set of valuation assumptions. The primary cash flow assumptions used to value such Borrower Loans, Loans Held for Sale and Notes include default rates derived from historical performance and discount rates applied to each credit grade based on the perceived credit risk of each credit grade. The following tables present the fair value hierarchy for assets and liabilities measured at fair value (in thousands): June 30, 2017 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 312,272 $ 312,272 Servicing Assets — — 13,297 13,297 Loans Held for Sale — — 95 95 Total Assets — — 325,664 325,664 Liabilities: Notes $ — $ — $ 311,410 $ 311,410 Servicing Liabilities — — 111 111 Loan Trailing Fee Liability 1,655 1,655 Total Liabilities $ — $ — $ 313,176 $ 313,176 December 31, 2016 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 315,627 $ 315,627 Servicing Assets — — 12,461 12,461 Loans Held for Sale — — 624 624 Total Assets — — 328,712 328,712 Liabilities: Notes $ — $ — $ 316,236 $ 316,236 Servicing Liabilities — — 198 198 Loan Trailing Fee Liability — — 665 665 Total Liabilities $ — $ — $ 317,099 $ 317,099 As Prosper Funding’s Borrower Loans, Loans Held for Sale, Notes and loan servicing rights do not trade in an active market with readily observable prices, Prosper Funding uses significant unobservable inputs to measure the fair value of these assets and liabilities. Financial instruments are categorized in the level 3 valuation hierarchy based on the significance of unobservable factors in the overall fair value measurement. These fair value estimates may also include observable, actively quoted components derived from external sources. As a result, the realized and unrealized gains and losses for assets and liabilities within the level 3 category may include changes in fair value that were attributable to both observable and unobservable inputs. Significant Unobservable Inputs The following tables present quantitative information about the significant unobservable inputs used for Prosper Funding’s level 3 fair value measurements at June 30, 2017 and December 31, 2016 : Borrower Loans, Loans Held for Sale and Notes: Range Unobservable Input June 30, 2017 December 31, 2016 Discount rate 4.3% - 15.2% 4.0% - 15.9% Default rate 1.9% - 15.2% 1.7% - 14.9% Servicing Rights Range Unobservable Input June 30, 2017 December 31, 2016 Discount rate 15% - 25% 15% - 25% Default rate 1.6% - 15.7% 1.5% - 15.2% Prepayment rate 14.4% - 26.7% 13.6% - 26.6% Market servicing rate 0.625 % 0.625 % The changes in the Borrower Loans, Loans Held for Sale and Notes, which are Level 3 assets and liabilities measured at fair value on a recurring basis are as follows (in thousands): Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at January 1, 2017 $ 315,627 $ (316,236 ) $ 624 $ 15 Originations 106,940 (106,506 ) 1,245,826 1,246,260 Principal repayments (97,492 ) 100,274 (42 ) 2,740 Borrower Loans sold to third parties (1,990 ) — (1,246,316 ) (1,248,306 ) Other changes 9 266 (3 ) 272 Change in fair value (10,822 ) 10,792 6 (24 ) Balance at June 30, 2017 $ 312,272 $ (311,410 ) $ 95 $ 957 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at January 1, 2016 $ 297,273 $ (297,405 ) $ 32 $ (100 ) Originations 109,215 (109,147 ) 1,358,011 1,358,079 Principal repayments (82,376 ) 83,119 (136 ) 607 Borrower Loans sold to third parties (1,138 ) 1,081 (1,353,202 ) (1,353,259 ) Other changes (6 ) (33 ) — (39 ) Change in fair value (12,934 ) 12,855 — (79 ) Balance at June 30, 2016 $ 310,034 $ (309,530 ) $ 4,705 $ 5,209 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at April 1, 2017 $ 317,536 $ (316,944 ) $ 109 $ 701 Originations 50,260 (49,692 ) 721,829 722,397 Principal repayments (48,048 ) 48,695 (14 ) 633 Borrower Loans sold to third parties (869 ) — (721,829 ) (722,698 ) Other changes 10 (156 ) — (146 ) Change in fair value (6,617 ) 6,687 — 70 Balance at June 30, 2017 $ 312,272 $ (311,410 ) $ 95 $ 957 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at April 1, 2016 $ 303,243 $ (302,357 ) $ 30 $ 916 Originations 54,044 (53,873 ) 426,591 426,762 Principal repayments (41,390 ) 41,057 (131 ) (464 ) Borrower Loans sold to third parties (525 ) 499 (421,784 ) (421,810 ) Other changes (2 ) (191 ) — (193 ) Change in fair value (5,336 ) 5,335 (1 ) (2 ) Balance at June 30, 2016 $ 310,034 $ (309,530 ) $ 4,705 $ 5,209 The following table presents additional information about Level 3 servicing assets and liabilities recorded at fair value for the three months ended June 30, 2017 (in thousands). Servicing Assets Servicing Liabilities Fair Value at January 1, 2017 12,461 198 Additions 6,532 — Less: Changes in fair value (5,696 ) (87 ) Fair Value at June 30, 2017 13,297 111 Servicing Assets Servicing Liabilities Fair Value at January 1, 2016 13,605 484 Additions 5,750 9 Less: Changes in fair value (5,557 ) (169 ) Fair Value at June 30, 2016 13,798 324 Servicing Assets Servicing Liabilities Fair Value at April 1, 2017 12,190 147 Additions 3,768 — Less: Changes in fair value (2,661 ) (36 ) Fair Value at June 30, 2017 13,297 111 Servicing Assets Servicing Liabilities Fair Value at April 1, 2016 14,929 398 Additions 1,729 — Less: Changes in fair value (2,860 ) (74 ) Fair Value at June 30, 2016 13,798 324 The following table presents additional information about level 3 Loan Trailing Fee Liability measured at fair value on a recurring basis (in thousands): Balance at January 1, 2017 665 Issuances 1,216 Cash payment of Loan Trailing Fee (351 ) Change in fair value 125 Balance at June 30, 2017 1,655 Significant Recurring Level 3 Fair Value Asset and Liability Input Sensitivity Key economic assumptions and the sensitivity of the current fair value to immediate changes in those assumptions at June 30, 2017 for Borrower Loans, Loans Held for Sale and Notes funded are presented in the following table (in thousands, except percentages): Borrower Loans and Loans Held for Sale Notes Discount rate assumption: 7.55 % * 7.55 % * Resulting fair value from: 100 basis point increase $ 309,203 $ 308,250 200 basis point increase 306,119 305,170 Resulting fair value from: 100 basis point decrease $ 315,614 $ 314,653 200 basis point decrease 318,948 317,984 Default rate assumption: 12.96 % * 12.96 % * Resulting fair value from: 100 basis point increase $ 308,608 $ 307,645 200 basis point increase 304,984 304,015 Resulting fair value from: 100 basis point decrease $ 316,150 $ 315,200 200 basis point decrease 319,980 319,038 * Represents weighted average assumptions considering all credit grades. Servicing Asset and Liability Fair Value Input Sensitivity: The following table presents the estimated impact on Prosper Funding’s estimated fair value of servicing assets and liabilities, calculated using different market servicing rates and different default rates as of June 30, 2017 (in thousands, except percentages). Servicing Assets Servicing Liabilities Market servicing rate assumptions 0.625 % 0.625 % Resulting fair value from: Market servicing rate increase to 0.65% 12,434 122 Market servicing rate decrease to 0.60% 14,160 100 Weighted average prepayment assumptions 20.09 % 20.09 % Resulting fair value from: Applying a 1.1 multiplier to prepayment rate 13,112 109 Applying a 0.9 multiplier to prepayment rate 13,484 113 Weighted average default assumptions 12.18 % 12.18 % Resulting fair value from: Applying a 1.1 multiplier to default rate 13,112 111 Applying a 0.9 multiplier to default rate 13,486 111 These sensitivities are hypothetical and should be evaluated with care. The effect on fair value of a 10% variation in assumptions generally cannot be determined because the relationship of the change in assumptions to the fair value may not be linear. Additionally, the impact of a variation in a particular assumption on the fair value is calculated while holding other assumptions constant. In reality, changes in one factor may lead to changes in other factors, which could impact the above hypothetical effects.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill Prosper’s goodwill balance of $36.4 million at June 30, 2017 did not change during the six months ended June 30, 2017 . We did no t record any goodwill impairment expense for the six months ended June 30, 2017 . A portion of the goodwill balance is considered held for sale, refer to Note 9 for more detail. Other Intangible Assets The following table presents the detail of other intangible assets for the period presented (dollars in thousands): June 30, 2017 Gross Carrying Value Accumulated Amortization Net Carrying Value Remaining Useful Life (In Years) User base and customer relationships $ 4,122 $ (3,775 ) $ 347 7.8 Developed technology 4,793 (3,278 ) $ 1,515 0.8 Brand name 60 (60 ) — — Total intangible assets subject to amortization $ 8,975 $ (7,113 ) $ 1,862 Prosper’s intangible asset balance was $1.9 million and $9.2 million at June 30, 2017 and December 31, 2016 , respectively. During the six months ended June 30, 2017 , certain intangible assets were made available for sale and as a result they were written down to fair value. This resulted in a $6.3 million impairment loss. Refer to Note 9 for more detail. The user base and customer relationship intangible assets are being amortized on an accelerated basis over a three to ten year period. The technology and brand name intangible assets are being amortized on a straight line basis over three to five years and one year , respectively. Amortization expense for the three months ended June 30, 2017 and 2016 was $0.2 million and $1.0 million , respectively. Amortization expense for the six months ended June 30, 2017 and 2016 was $1.0 million and $2.0 million , respectively. Estimated amortization of purchased intangible assets for future periods (excluding those held for sale) is as follows (in thousands): Year Ending December 31, Remainder of 2017 $ 355 2018 379 2019 279 2020 219 2021 500 Total $ 1,732

Assets Held for Sale

Assets Held for Sale	6 Months Ended
	Jun. 30, 2017
Assets Held-for-Sale [Abstract]
Assets Held for Sale	Assets Held for Sale As of June 30, 2017, the Company was actively marketing certain assets related to the Prosper Daily application. Through this process, the Company identified the specific assets to be sold and allocated goodwill based on the relative fair values of the assets held for sale and the assets that will be retained by the Company. The fair value of the assets held for sale is based on management's best estimates of what it expects to receive. This resulted in an impairment loss of $2.0 million and $6.3 million during the three and six months ended June 30, 2017, which is recorded in Other Expenses on the Condensed Consolidated Statement of Operations. Amounts classified as assets held for sale on June 30, 2017, are presented on the Company’s Condensed Consolidated Balance Sheet within their respective accounts, and include the following (in thousands): Intangible Assets $ 130 Goodwill 12 Total Assets Held for Sale $ 142

Other Liabilities

Other Liabilities	6 Months Ended
	Jun. 30, 2017
Other Liabilities [Abstract]
Other Liabilities	Other Liabilities Other Liabilities includes the following: June 30, 2017 December 31, 2016 Class action settlement liability $ — $ 2,996 Repurchase liability for unvested restricted stock awards 24 118 Loan trailing fee 1,655 665 Servicing liabilities 111 198 Deferred rent 4,133 4,469 Restructuring liability 3,414 6,052 Other 3,438 2,675 Total Other Liabilities $ 12,775 $ 17,173

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share The weighted average shares used in calculating basic and diluted net loss per share excludes certain shares that are disclosed as outstanding shares in the condensed consolidated balance sheets because such shares are restricted as they were associated with options that were early exercised and continue to remain unvested. Basic and diluted net loss per share was calculated as follows: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Numerator: Net loss available to common stockholders for basic and diluted EPS $ (41,405 ) $ (35,628 ) $ (65,426 ) $ (53,092 ) Denominator: Weighted average shares used in computing basic and diluted net loss per share 69,691,841 63,270,058 69,436,365 61,813,773 Basic and diluted net loss per share $ (0.59 ) $ (0.56 ) $ (0.94 ) $ (0.86 ) The following common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because including them would have been anti-dilutive: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (shares) (shares) (shares) (shares) Excluded securities: Convertible preferred stock issued and outstanding 177,388,428 177,388,425 177,388,428 177,388,425 Stock options issued and outstanding 60,938,265 43,719,604 53,040,604 41,694,271 Unvested stock options exercised 20,940 5,345,950 20,940 5,345,950 Restricted stock units — — — — Warrants issued and outstanding 1,199,403 962,113 1,199,403 792,449 Series E convertible preferred stock warrants 35,544,141 — 35,544,141 — Series F convertible preferred stock warrants 177,720,704 — 177,720,704 — Total common stock equivalents excluded from diluted net loss per common share computation 452,811,881 227,416,092 444,914,220 225,221,095 The number of shares issued and outstanding reflect a 5 -for- 1 forward stock split effected by PMI on February 16, 2016.

Convertible Preferred Stock, Wa

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit	6 Months Ended
	Jun. 30, 2017
Stockholders' Equity Note [Abstract]
Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit	Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit Convertible Preferred Stock and Warrants On December 16, 2016, PMI issued a warrant to purchase 20,267,135 shares of Series E-1 convertible preferred stock of PMI ("Series E-1") at an exercise price of $0.01 per share (the “First Series E-1 Warrant”) to Pinecone Investments LLC (“Pinecone”), an affiliate of Colchis Capital Management, L.P. (“Colchis”). On February 27, 2017, PMI issued to Pinecone a second warrant (the “Second Series E-1 Warrant,” and together with the First Series E-1 Warrant, the “Series E-1 Warrants”) to purchase 15,277,006 shares of Series E-1 at an exercise price of $0.01 per share. The Series E-1 Warrants are immediately exercisable, in whole or in part, by paying in cash the full purchase price payable in respect of the number of shares purchased. The Series E-1 Warrants were issued pursuant to the Warrant Agreement, dated December 16, 2016, between PMI and Colchis, as previously described in PMI’s Current Report on Form 8-K as filed with the Commission on December 22, 2016. In connection with a loan purchase agreement (“Consortium Purchase Agreement”) with affiliates of the Consortium ("Warrant Holders'") a warrant agreement was signed (the "Warrant Agreement"). Pursuant to the Warrant Agreement, PMI issued to the Consortium, three warrants (together, the “Series F Warrant”) to purchase up to in aggregate 177,720,706 shares of PMI’s Series F Preferred Stock at an exercise price of $0.01 per share (the “Warrant Shares”). The Warrant Holders' right to exercise the Series F Warrant is subject to monthly vesting during the term of the Consortium Purchase Agreement based upon the volume of loans the Consortium elects to purchase (if any) in each month, subject to certain cure rights such as offering additional loans for sale in subsequent periods (except that a certain portion of the Series F Warrant will be immediately exercisable as a result of loans purchased before the signing of the agreement). Under the terms of the Warrant Agreement, the Warrant Shares may also vest in full upon a change of control of PMI, insolvency of PMI or PFL certain breaches of contract by PMI or PFL that are not cured within a defined cure period and upon the occurrence of certain events set forth in the Warrant Agreement. The Series F Warrant will be exercisable with respect to vested Warrant Shares, in whole or in part, at any time prior to the tenth anniversary of its date of issuance. The number of shares underlying the Series F Warrant may be adjusted following certain events such as stock splits, dividends, reclassifications, and certain other issuances by PMI. The number of authorized, issued and outstanding shares, their par value and liquidation preference for each series of convertible preferred stock as of June 30, 2017 are disclosed in the table below (amounts in thousands except share and per share amounts): Convertible Preferred Stock Par Value Authorized shares Outstanding Liquidation Preference (outstanding shares) Series A $ 0.01 68,558,220 68,558,220 $ 19,774 Series A-1 0.01 24,760,915 24,760,915 49,522 Series B 0.01 35,775,880 35,775,880 21,581 Series C 0.01 24,404,770 24,404,770 70,075 Series D 0.01 23,888,640 23,888,640 165,000 Series E-1 0.01 35,544,141 — — Series E-2 0.01 16,858,078 — — Series F 0.01 177,720,707 3 — 407,511,351 177,388,428 $ 325,952 The number of shares issued and outstanding reflect a 5 -for-1 forward stock split effected by PMI on February 16, 2016. Dividends Dividends on shares of the Series A, Series B, Series C, Series D, Series E-1, Series E-2 and Series F convertible preferred stock are payable only when, as, and if declared by the Board of Directors. No dividends will be paid with respect to the common stock until any declared dividends on the Series A, Series B, Series C, Series D, Series E-1, Series E-2 and Series F convertible preferred stock have been paid or set aside for payment to the Series A, Series B, Series C, Series D, Series E-1, Series E-2 and Series F convertible preferred stockholders. After payment of any such dividends, any additional dividends or distributions will be distributed among all holders of common stock and preferred stock in proportion to the number of shares of common stock that would be held by each such holder if all shares of preferred stock were converted to common stock at the then effective conversion rate. The Series A-1 convertible preferred shares have no dividend rights. To date, no dividends have been declared on any of the PMI’s preferred stock or common stock. Conversion Under the terms of PMI’s amended and restated certificate of incorporation, the holders of preferred stock have the right to convert such preferred stock into common stock at any time. In addition, all preferred stock automatically converts into common stock (i) immediately prior to the closing of an Initial Public Offering (“IPO”) that values Prosper at least at $2 billion and that results in aggregate proceeds to Prosper of at least $100 million or (ii) upon a written request from the holders of at least 60% of the voting power of the outstanding preferred stock (on an as-converted basis), provided that (i) the Series A-1 convertible preferred stock shall not be converted without at least 14% of the voting power of the outstanding Series A-1 convertible preferred stock; (ii) the Series D shall not be converted without at least 60% of the voting power of the outstanding Series D; (iii) the Series E-1 and Series E-2 shall not be converted without at least 60% of the voting power of the outstanding Series E-1 and Series E-2, voting together as a single class; and (iv) the Series F shall not be converted without at least 60% of the voting power of the outstanding Series F. In addition, if a holder of the Series A convertible preferred stock has converted any of the Series A convertible preferred stock, then all of such holder’s shares of Series A-1 convertible preferred stock also will be converted upon a liquidation event. In lieu of any fractional shares of common stock to which a holder would otherwise be entitled, PMI shall pay such holder cash in an amount equal to the fair market value of such fractional shares, as determined by its Board of Directors. At present, the Series A, Series B, Series C, Series D, Series E-1, Series E-2 and the Series F convertible preferred stock converts into PMI common stock at a 1 :1 ratio while the Series A-1 convertible preferred stock converts into common stock at a 1,000,000 :1 ratio Liquidation Rights PMI’s convertible preferred stock has been classified as temporary equity on the Consolidated Balance Sheets. The preferred stock is not redeemable; however, upon in the event of a voluntary or involuntary liquidation, dissolution, change in control or winding up of PMI, holders of the convertible preferred stock may have the right to receive its liquidation preference under the terms of PMI’s certificate of incorporation. Each holder of Series E-1, Series E-2 and Series F convertible preferred stock is entitled to receive prior and in preference to any distribution of proceeds from a liquidation event to the holders of Series A, Series B, Series C, Series D and Series A-1 preferred stock or common stock, an amount per share for (i) each share of Series E-1 convertible preferred stock equal to the sum of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share, (ii) each share of Series E-2 convertible preferred stock equal to the sum of two-thirds the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share, and (iii) each share of Series F convertible preferred stock equal to the sum of two-thirds of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share. After the payment or setting aside for payment to the holders of Series E-1, Series E-2, and Series F convertible preferred stock, each holder of Series A, Series B, Series C and Series D, Series E-2 and Series F convertible preferred stock is entitled to receive, on a pari passu basis, prior to and in preference to any distribution of proceeds from a liquidation event to the holders of Series A-1 preferred stock or common stock, (i) an amount per share for each share of Series E-2 and Series F convertible preferred stock equal to the sum of one-third of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share, and (ii) an amount per share for each share of Series A, Series B, Series C and Series D convertible preferred stock equal to the sum of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share. After the payment or setting aside for payment to the holders of Series A, Series B, Series C, Series D, Series E-1, Series E-2 and Series F convertible preferred stock, the holders of Series A-1 convertible preferred stock are entitled to receive, prior and in preference to any distribution of proceeds to the holders of common stock an amount per share for each such share of Series A-1 convertible preferred stock equal to the sum of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share. After the payment or setting aside for payment to the holders of Series A, Series B, Series C, Series D, Series E-1, Series E-2, Series F convertible preferred stock and Series A-1 preferred stock, the entire remaining proceeds legally available for distribution will be distributed pro rata to the holders of Series A preferred stock and common stock in proportion to the number of shares of common stock held by them assuming the Series A preferred stock has been converted into shares of common stock at the then effective conversion rate, provided that the maximum aggregate amount per share of Series A convertible preferred stock which the holders of Series A convertible preferred stock shall be entitled to receive is three times the original issue price for the Series A convertible preferred stock. At present, the liquidation preferences are equal to $0.29 per share for the Series A convertible preferred stock, $2.00 per share for the Series A-1 convertible preferred stock, $0.60 per share for the Series B convertible preferred stock, $2.87 per share for the Series C convertible preferred stock, $6.91 for the Series D convertible preferred stock, $0.84 for the Series E-1 convertible preferred stock, $0.84 for the Series E-2 convertible preferred stock, and $0.84 for the Series F convertible preferred stock. Voting Each holder of shares of convertible preferred stock is entitled to the number of votes equal to the number of shares of common stock into which such shares of convertible preferred stock could be converted and has voting rights and powers equal to the voting rights and powers of the common stock. The holders of convertible preferred stock and the holders of common stock vote together as a single class (except with respect to certain matters that require separate votes or as required by law), and are entitled to notice of any stockholders’ meeting in accordance with the bylaws of PMI. Convertible Preferred Stock Warrant L iability Series E-1 Warrants In connection with the Settlement and Release Agreement dated November 17, 2016 among PMI, PFL and Colchis, on December 16, 2016, PMI issued the First Series E-1 Warrant. The Second Series E-1 Warrant for an additional 15,277,006 shares of Series E-1 convertible preferred stock were granted on the signing of the Consortium Purchase Agreement on February 27, 2017. The warrants expire ten years from the date of issuance. For the six months ended June 30, 2017 , Prosper recognized $14.9 million of expense from the re-measurement of the fair value of the warrants. The expense is recorded through other expenses in the statement of operations. To determine the fair value of the Series E-1 Convertible Preferred Stock Warrants, the Company first determined the value of a share of a Series E-1 convertible preferred stock. To determine the fair value of the convertible preferred stock, the Company first derived the business enterprise value (“BEV”) of the Company using valuation methods, including a combination of methods, as deemed appropriate under the circumstances applicable at the valuation date. Once the Company determined an estimated BEV, the option pricing method ("OPM") was used to allocate the BEV to the various classes of the Company’s equity, including the Company’s preferred stock. The concluded per share value for the Series E-1 convertible preferred stock was utilized as an input to the Black-Scholes option pricing model. The Company determined the fair value of the outstanding convertible Series E-1 preferred stock warrants utilizing the following assumptions as of the following dates: June 30, 2017 December 31, 2016 Volatility 40 % 40% Risk-free interest rate 2.28 % 2.45% Remaining contractual term 9.55 years 9.96 years Dividend yield — % —% The above assumptions were determined as follows: Volatility: The volatility is derived from historical volatilities of several unrelated publicly listed peer companies over a period approximately equal to the term of the warrant because the Company has limited information on the volatility of the preferred stock since there is currently no trading history. When making the selections of industry peer companies to be used in the volatility calculation, the Company considered the size, operational, and economic similarities to the Company’s principal business operations. Risk-Free Interest Rate: The risk-free interest rate is based on the U.S. Treasury yield in effect as of the period end date and for zero coupon U.S. Treasury notes with maturities approximately equal to the term of the warrant. Remaining Contractual Term : The remaining contractual term represents the time from the date of the valuation to the expiration of the warrant. Dividend Yield: The expected dividend assumption is based on the Company’s current expectations about the Company’s anticipated dividend policy. Series F Warrants In connection with the Consortium Purchase Agreement (as described in Note 16), PMI issued warrants to purchase up to 177,720,706 of PMI's Series F convertible preferred share at $0.01 per share. For the three months ended June 30, 2017 , Prosper recognized $7.5 million of expense from the re-measurement of the fair value of the warrants. The expense is recorded through other expenses in the condensed consolidated statement of operations. To determine the fair value of the Series F Convertible Preferred Stock Warrants, the Company first determined the value of a share of a Series F convertible preferred stock. To determine the fair value of the convertible preferred stock, the Company first derived the BEV of the Company using valuation methods, including a combination of methods, as deemed appropriate under the circumstances applicable at the valuation date. Once the Company determined an estimated BEV, the OPM was used to allocate the BEV to the various classes of the Company’s equity, including the Company’s preferred stock. The concluded per share value for the Series F convertible preferred stock warrants utilized the Black-Scholes option pricing model. The Company determined the fair value of the outstanding convertible Series F preferred stock warrants utilizing the following assumptions as of June 30, 2017 : June 30, 2017 Volatility 40 % Risk-free interest rate 2.29 % Remaining contractual term (in years) 9.66 Dividend yield — % The above assumptions were determined as follows: Volatility : The volatility is derived from historical volatilities of several unrelated publicly listed peer companies over a period approximately equal to the term of the warrant because the Company has limited information on the volatility of the preferred stock since there is currently no trading history. When making the selections of industry peer companies to be used in the volatility calculation, the Company considered the size, operational, and economic similarities to the Company’s principal business operations. Risk-Free Interest Rate: The risk-free interest rate is based on the U.S. Treasury yield in effect as of the period end date and for zero coupon U.S. Treasury notes with maturities approximately equal to the term of the warrant. Remaining Contractual Term: The remaining contractual term represents the time from the date of the valuation to the expiration of the warrant. Dividend Yield: The expected dividend assumption is based on the Company’s current expectations about the Company’s anticipated dividend policy. The combined activity of the Convertible Preferred Stock Warrant Liability for the six months ended June 30, 2017 is as follows (in thousands): Balance at January 1, 2017 $ 21,711 Warrants Vested 25,586 Change in Fair Value 22,817 Balance at June 30, 2017 $ 70,114 Common Stock PMI, through its amended and restated certificate of incorporation, as amended, is the sole issuer of common stock and related options, RSUs and warrants. On February 16, 2016, PMI amended and restated its certificate of incorporation to, among other things, effect a 5 -for-1 forward stock split. On May 31, 2016, PMI further amended its amended and restated certificate of incorporation to increase the number of shares of common stock authorized for issuance. The total number of shares of stock which PMI has the authority to issue is 957,511,351 , consisting of 550,000,000 shares of common stock, $0.01 par value per share, and 407,511,351 shares of preferred stock, $0.01 par value per share. As of June 30, 2017 , 70,719,747 shares of common stock were issued and 69,783,812 shares of common stock were outstanding. As of December 31, 2016 , 70,843,044 shares of common stock were issued and 69,907,109 shares of common stock were outstanding. Each holder of common stock is entitled to one vote for each share of common stock held. Common Stock Issued upon Exercise of Stock Options During the six months ended June 30, 2017 , PMI issued 134,633 shares of common stock upon the exercise of vested options for cash proceeds of $14 thousand . Certain options are eligible for exercise prior to vesting. These unvested options may be exercised for restricted shares of common stock that have the same vesting schedule as the options. Prosper records a liability for the exercise price paid upon the exercise of unvested options, which is reclassified to common stock and additional paid-in capital as the shares vest. Should the holder’s employment be terminated, the unvested restricted shares are subject to repurchase by PMI at an amount equal to the exercise price paid for such shares. At June 30, 2017 and December 31, 2016 , there were 20,940 and 1,126,210 shares, respectively, of restricted stock outstanding that remain unvested and subject to Prosper’s right of repurchase. For the six months ended June 30, 2017 , PMI repurchased 266,130 shares of restricted stock for $64 thousand upon termination of employment of various employees

Shared Based Incentive Plan and

Shared Based Incentive Plan and Compensation	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shared Based Incentive Plan and Compensation	Share Based Incentive Plan and Compensation In 2005, PMI’s stockholders approved the adoption of the 2005 Stock Plan. On December 1, 2010, PMI’s stockholders approved the adoption of the Amended and Restated 2005 Stock Plan (the “2005 Plan”). The 2005 Plan expired during the year ending December 31, 2015 and PMI’s stockholders approved the adoption of the 2015 Equity Incentive Plan. On February 15, 2016, PMI’s stockholders approved the adoption of an Amendment No. 1 to the 2015 Equity Incentive Plan, and on May 31, 2016, PMI’s stockholders approved the adoption of an Amendment No. 2 to the 2015 Equity Incentive Plan (as amended to date, the “2015 Plan”). In March 2015, the 2005 Plan expired, except that any awards granted under the 2005 Plan prior to its expiration remain in effect pursuant to their terms. As of June 30, 2017 under the 2015 Plan, up to 60,241,343 shares of common stock are reserved and may be granted to employees, directors, and consultants by PMI’s board of directors and stockholders to promote the success of Prosper’s business. Options generally vest 25% one year from the vesting commencement date and 1/48t h per month thereafter or vest 50% one year from the vesting date and 1/48 per month thereafter or vest 50% two years from the vesting commencement date and 1/48t h per month thereafter or vest 1/36t h per month from the vesting commencement date. In no event are options exercisable more than ten years after the date of grant. At June 30, 2017 , there were 9,817,115 shares available for grant under the 2015 Plan and zero shares available for grant under the 2005 Plan. The number of options, restricted stock units and amounts per share reflects a 5 -for-1 forward stock split effected by PMI on February 16, 2016. Stock Option Reprice On May 3, 2016, the Compensation Committee of the Board of Directors of PMI approved a stock option repricing program, (the “2016 Reprice”) authorizing PMI’s officers to reprice certain outstanding stock options held by employees and directors that have exercise prices above the current fair market value of PMI’s common stock. The repricing was effected on May 16, 2016 for eligible directors and employees located in the United States and on May 19, 2016 for eligible employees located in Israel. On March 17, 2017, the Compensation Committee of the Board of Directors of PMI approved a stock option repricing program, (the “2017 Reprice” and together with the 2016 Reprice, the "Repricings") authorizing PMI’s officers to reprice certain outstanding stock options held by employees and directors that have exercise prices above the current fair market value of PMI’s common stock. The repricing was effected on March 17, 2017 for eligible directors and employees. Prosper believes that the Repricings of such stock options will encourage the continued service of valued employees and directors, and motivate such service providers to perform at high levels, both of which are critical to Prosper’s continued success. Prosper expects to incur additional stock based compensation charges as a result of the Repricings. The financial statement impact of the above Repricings is $0.1 million in the three months ended June 30, 2017 and $0.9 million (net of forfeitures) that will be recognized over the remaining weighted average vesting period of 1.9 years . Early Exercised Stock Options The balance of stock options that were early exercised under the 2005 Plan as of June 30, 2017 is not material. Stock Option Activity Stock option activity under the 2005 Plan and 2015 Plan is summarized for the six months ended June 30, 2017 below: Options Issued and Outstanding Weighted- Average Exercise Price Balance as of January 1, 2017 41,395,719 $ 1.48 Options issued 30,388,611 0.22 Options exercised – vested (134,633 ) 0.11 Options forfeited (12,089,870 ) 1.17 Options expired (2,500 ) 0.22 Balance as of June 30, 2017 59,557,327 $ 0.21 Options vested and expected to vest as of June 30, 2017 47,563,036 0.21 Options vested and exercisable at June 30, 2017 21,119,436 0.18 Due to the timing of the 2017 Reprice, the ending weighted average exercise price shown above reflects repriced options while the opening weighted average exercise price does not. Other Information Regarding Stock Options Additional information regarding common stock options outstanding as of June 30, 2017 is as follows: Options Outstanding Options Vested and Exercisable Range of Exercise Prices Number Outstanding Weighted – Avg. Remaining Life Weighted –Avg. Exercise Price Number Vested Weighted – Avg. Exercise Price $ 0.02 - 0.20 8,275,145 6.56 $ 0.11 8,275,145 $ 0.11 0.20 - 0.50 51,260,062 9.09 0.22 12,822,171 0.22 0.50 - 1.13 22,120 7.35 1.13 22,120 1.13 $ 0.02 - 1.13 59,557,327 8.74 $ 0.20 21,119,436 $ 0.18 The fair value of options granted to employees is estimated on the grant date using the Black-Scholes option valuation model. This valuation model for stock-based compensation expense requires Prosper to make assumptions and judgments about the variables used in the calculation, including the fair value of PMI’s common stock, the expected term (the period of time that the options granted are expected to be outstanding), the volatility of PMI’s common stock, a risk-free interest rate, and expected dividends. Given the absence of a publicly traded market, Prosper considered numerous objective and subjective factors to determine the fair value of PMI’s common stock at each grant date. These factors included, but were not limited to: (i) contemporaneous valuations of common stock performed by unrelated third-party specialists; (ii) the prices for PMI’s preferred stock sold to outside investors; (iii) the rights, preferences and privileges of PMI’s preferred stock relative to PMI’s common stock; (iv) the lack of marketability of PMI’s common stock; (v) developments in the business; (vi) secondary transactions of PMI’s common and preferred shares and (vii) the likelihood of achieving a liquidity event, such as an initial public offering or a merger or acquisition of Prosper, given prevailing market conditions. As PMI’s stock is not publicly traded volatility for stock options is based on an average of the historical volatilities of the common stock of several entities with characteristics similar to those of Prosper. The expected term assumptions were determined based on the vesting terms, exercise terms and contractual lives of the options using the simplified method. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected life of the option. Prosper uses an expected dividend yield of zero as it does not anticipate paying any dividends in the foreseeable future. Prosper also estimates forfeitures of unvested stock options. Expected forfeitures are based on Prosper’s historical experience. To the extent actual forfeitures differ from the estimates, the difference will be recorded as a cumulative adjustment in the period estimates are revised. No compensation cost is recorded for options that do not vest. The fair value of PMI’s stock option awards granted during the three months ended June 30, 2017 and 2016 was estimated at the date of grant using the Black-Scholes model with the following average assumptions: Three Months Ended Six Months Ended June 30, 2017 2016 2017 2016 Volatility of common stock N/A 50.88 % 50.28 % 50.88 % Risk-free interest rate N/A 1.29 % 2.12 % 1.29 % Expected life N/A 5.8 years 5.7 years 5.8 years Dividend yield N/A 0 % 0 % 0 % Restricted Stock Unit Activity During the six months ended June 30, 2017 , PMI granted restricted stock units (“RSUs”) to certain employees that are subject to three -year vesting terms or four year vesting terms and the occurrence of a liquidity event. The aggregate fair value of the RSUs granted was $3 thousand . The following table summarizes the activities for PMI’s RSUs during the six months ended June 30, 2017 : Number of Shares Weighted-Average Grant Date Fair Value Unvested - December 31, 2016 1,995,159 $ 2.16 Granted 12,000 0.22 Vested — — Forfeited (509,479 ) 2.18 Unvested - June 30, 2017 1,497,680 $ 2.14 The following table presents the amount of stock-based compensation related to stock-based awards granted to employees recognized in Prosper’s condensed consolidated statements of operations during the three months ended June 30, 2017 and 2016 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Origination and servicing $ 328 $ 579 $ 545 $ 1,018 Sales and marketing 141 896 311 1,632 General and administrative 2,843 4,884 5,956 8,815 Restructuring — 45 — 45 Total stock based compensation $ 3,312 $ 6,404 $ 6,812 $ 11,510 During the three months ended June 30, 2017 and 2016 , Prosper capitalized $75 thousand and $225 thousand respectively, of stock-based compensation as internal use software and website development costs. As of June 30, 2017 , the unamortized stock-based compensation expense adjusted for forfeiture estimates related to Prosper’s employees’ unvested stock-based awards was approximately $21.2 million , which will be recognized over the remaining weighted-average vesting period of approximately 2.0 years.

Restructuring

Restructuring	6 Months Ended
	Jun. 30, 2017
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring Summary of Restructuring Plan On May 3, 2016, Prosper adopted a strategic restructuring of its business. This restructuring was intended to streamline our operations and support future growth efforts. Under this restructuring, Prosper closed its Salt Lake City, Utah location. As a result of this restructuring, Prosper terminated 167 employees across all locations. In December 2016, Prosper shut down its Tel Aviv location, resulting in the termination of 31 employees. In addition to the employment costs associated with the restructuring, Prosper is also marketing for sublease our existing office space that is no longer needed due to the reduction in headcount. Other than accretion and changes in sublease loss estimates, Prosper does not expect any additional restructuring charges related to this restructuring. The following table summarizes the activities related to Prosper's restructuring plan (in thousands): Severance Related Facilities Related Total Balance January 1, 2017 $ 597 $ 6,052 $ 6,649 Adjustments to expense (13 ) 321 308 Sublease cash receipts — 16 16 Less: Cash paid (584 ) (3,193 ) (3,777 ) Balance June 30, 2017 $ — $ 3,196 $ 3,196

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Income Taxes	Income Taxes For the three months ended June 30, 2017 and 2016 , Prosper recognized $97 thousand and $105 thousand of income tax expense, respectively. For the six months ended June 30, 2017 and 2016 , Prosper recognized $262 thousand and $270 thousand of income tax expense, respectively. The income tax expense relates to state income tax expense and the amortization of tax deductible goodwill which gives rise to an indefinite-lived deferred tax liability. No other income tax expense or benefit was recorded for the three or six month periods ended June 30, 2017 and 2016 due to a full valuation allowance recorded against our deferred tax assets. Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to utilize our existing deferred tax assets. On the basis of this evaluation, it is not more likely than not that our deferred tax assets will be realized and therefore a full valuation allowance has been recorded.
Prosper Funding LLC
Entity Information [Line Items]
Income Taxes	Income Taxes Prosper Funding incurred no income tax provision for the six months ended June 30, 2017 and 2016 . Prosper Funding is a US disregarded entity and its income and loss is included in the return of its parent, PMI. Since PMI is in a loss position, is not currently subject to income taxes, and has fully reserved its deferred tax asset, the net effective tax rate for Prosper Funding is 0% .

Consortium Purchase Agreement

Consortium Purchase Agreement	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Consortium Purchase Agreement	Consortium Purchase Agreement On February 27, 2017, Prosper entered into series of agreements (the "Consortium Purchase Agreement") with a consortium of investors (the "Consortium"). Under the Consortium Purchase Agreement the Consortium has agreed to purchase borrower loans in an aggregate principal amount of up to $5.0 billion (including certain loans purchased by one of the investors prior to the date of the Consortium Agreement). PFL will be obligated to offer for purchase minimum monthly volumes of eligible loans to the Consortium, for the Consortium to elect to purchase. In connection with the above agreement to purchase PMI issued to the Consortium, three warrants (together, the “Series F Warrant”) to purchase up to in aggregate 177,720,706 shares of PMI’s Series F Preferred Stock at an exercise price of $0.01 per share (the “Warrant Shares”). The Consortium’s right to exercise the Series F Warrant is subject to monthly vesting during the term of the Consortium Purchase Agreement based upon the volume of loans Purchaser elects to purchase (if any) in each month, subject to certain cure rights such as offering additional loans for sale in subsequent periods (except that a certain portion of the Series F Warrant will be immediately exercisable as a result of loans purchased before the signing of the agreement). Under the terms of the Warrant Agreement, the Warrant Shares may also vest in full upon a change of control of PMI, insolvency of PMI or PFL, certain breaches of contract by PMI or PFL that are not cured within a defined cure period and upon the occurrence of certain other events set forth in the Warrant Agreement. On vesting of the Series F warrants, Prosper records a liability as Convertible Preferred Stock Warrant Liability on the Condensed Consolidated Balance Sheet at fair value and a corresponding amount as "Fair Value of Warrants Vested on Sale of Borrower Loans" on the Condensed Consolidated Statement of Operations. Subsequent changes in the fair value of the vested warrants are recorded in "Other Expenses" on the Condensed Consolidated Statement of Operations. Additionally as part of signing of the Consortium Purchase Agreement certain rebates previously issued were settled by the issuance of vested Series F Convertible Preferred Stock Warrants. The difference in fair value of these warrants over the cash settlement price is recorded in "Other Expense" on the Condensed Consolidated Statement of Operations. Commitments and Contingencies Future Minimum Lease Payments Prosper has entered into various non-cancelable operating leases for certain offices with contractual lease periods expiring between 2022 and 2027 . Future minimum rental payments under these leases as of June 30, 2017 are as follows (in thousands): Remaining six months of 2017 2,762 2018 5,690 2019 6,026 2020 6,193 2021 6,170 2022 6,076 Thereafter 8,480 Total future operating lease obligations $ 41,397 The payments in the above table include amounts that have been accrued for as part of the restructuring liability in Note 14. Restructuring accrual balances related to operating facility leases were $3.4 million at June 30, 2017 . Rental expense under operating lease arrangements was $1.2 million and $1.9 million for the three months ended June 30, 2017 and 2016 , respectively. Rental expense under operating lease arrangements was $2.5 million and $3.7 million for the six months ended June 30, 2017 and 2016 , respectively. Operating Commitments Prosper has entered into an agreement with WebBank, under which all Borrower Loans originated through the marketplace are made by WebBank under its bank charter. Pursuant to the agreement, the marketing fee that Prosper receives in connection with the origination of each loan is partially reduced by an amount (the “Designated Amount”) calculated as a percentage of the principal amount of such loan based on the aggregate principal amount of loans originated for the applicable month. To the extent the aggregate Designated Amount for all loans originated during any month is less than $143,500 , Prosper is required to pay WebBank an amount equal to such deficiency. Accordingly, t he minimum fee for the remaining nine months ended December 31, 2017 is $0.9 million . The minimum fee is $1.7 million and $0.9 million in each of the years 2018 and 2019, respectively. Additionally, under the agreement with WebBank, Prosper is required to maintain a minimum net liquidity of $15 million at all times during the term of the agreement. Net liquidity is defined as the sum of Cash, Cash Equivalents and Available for Sale Investments. Violation of this covenant can result in termination of the contract with WebBank. At June 30, 2017 , Prosper was in compliance with the covenant. Loan Purchase Commitments Prosper has entered into an agreement with WebBank to purchase $40.9 million of Borrower Loans that WebBank originated during the last two business days of the quarter ended June 30, 2017 and the first business day of the quarter ending September 30, 2017. Prosper will purchase these Borrower Loans within the first three business days of the quarter ending September 30, 2017. Repurchase and Indemnification Contingency Under the terms of the loan purchase agreements between Prosper and investors that participate in the Whole Loan Channel, Prosper may, in certain circumstances, become obligated to repurchase a Borrower Loan from an investor. Generally, these circumstances include the occurrence of verifiable identity theft, the failure to properly follow loan listing or bidding protocols, or a violation of the applicable federal, state, or local lending laws. The fair value of the indemnification and repurchase obligation is estimated based on historical experience and the initial fair value is insignificant. Prosper recognizes a liability for the repurchase and indemnification obligation when the Borrower Loans are issued. Indemnified or repurchased Borrower Loans associated with violations of federal, state, or local lending laws or verifiable identity theft are written off at the time of repurchase or at the time an indemnification payment is made. The maximum potential amount of future payments associated under this obligation is the outstanding balances of the Borrower Loans issued through the Whole Loan Channel, which at June 30, 2017 is $3,557 million . Prosper has accrued $1.1 million and $0.6 million as of June 30, 2017 and December 31, 2016 , respectively, in regard to this obligation. Securities Law Compliance From inception through October 16, 2008, Prosper sold approximately $178.0 million of Borrower Loans to investors through its old platform structure, whereby Prosper assigned promissory notes directly to investors. Prosper did not register the offer and sale of the promissory notes corresponding to these Borrower Loans under the Securities Act or under the registration or qualification provisions of any state securities laws. Prosper believes that the question of whether or not the operation of the platform during this period constituted an offer or sale of “securities” involved a complicated factual and legal analysis and was uncertain. If the sales of promissory notes offered through the platform during this period were viewed as a securities offering, Prosper would have failed to comply with the registration and qualification requirements of federal and state laws. In 2008, plaintiffs filed a class action lawsuit against Prosper and certain of its executive officers and directors in the Superior Court of California, County of San Francisco, California. The suit was brought on behalf of all promissory note purchasers on the platform from January 1, 2006 through October 14, 2008. The lawsuit alleged that Prosper offered and sold unqualified and unregistered securities in violation of the California and federal securities laws. On July 19, 2013 solely to avoid the costs, risks and uncertainties inherent in litigation, and without admitting any liability or wrongdoing, the parties to the class action litigation agreed to enter into a settlement to resolve all claims related thereto (the “Settlement”). In connection with the Settlement, Prosper agreed to pay an aggregate amount of $10 million into a settlement fund, split into four annual installments of $2 million in 2014, $2 million in 2015, $3 million in 2016 and $3 million in 2017. The Settlement received final approval in a final order and judgment entered by the Superior Court on April 16, 2014. Pursuant to the final order and judgment, the claims in the class action were dismissed, and the defendants were released by the plaintiffs from all claims that were or could have been asserted concerning the issues alleged in the class action lawsuit. All annual installments have been made prior to June 30, 2017 .

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Commitments and Contingencies	Consortium Purchase Agreement On February 27, 2017, Prosper entered into series of agreements (the "Consortium Purchase Agreement") with a consortium of investors (the "Consortium"). Under the Consortium Purchase Agreement the Consortium has agreed to purchase borrower loans in an aggregate principal amount of up to $5.0 billion (including certain loans purchased by one of the investors prior to the date of the Consortium Agreement). PFL will be obligated to offer for purchase minimum monthly volumes of eligible loans to the Consortium, for the Consortium to elect to purchase. In connection with the above agreement to purchase PMI issued to the Consortium, three warrants (together, the “Series F Warrant”) to purchase up to in aggregate 177,720,706 shares of PMI’s Series F Preferred Stock at an exercise price of $0.01 per share (the “Warrant Shares”). The Consortium’s right to exercise the Series F Warrant is subject to monthly vesting during the term of the Consortium Purchase Agreement based upon the volume of loans Purchaser elects to purchase (if any) in each month, subject to certain cure rights such as offering additional loans for sale in subsequent periods (except that a certain portion of the Series F Warrant will be immediately exercisable as a result of loans purchased before the signing of the agreement). Under the terms of the Warrant Agreement, the Warrant Shares may also vest in full upon a change of control of PMI, insolvency of PMI or PFL, certain breaches of contract by PMI or PFL that are not cured within a defined cure period and upon the occurrence of certain other events set forth in the Warrant Agreement. On vesting of the Series F warrants, Prosper records a liability as Convertible Preferred Stock Warrant Liability on the Condensed Consolidated Balance Sheet at fair value and a corresponding amount as "Fair Value of Warrants Vested on Sale of Borrower Loans" on the Condensed Consolidated Statement of Operations. Subsequent changes in the fair value of the vested warrants are recorded in "Other Expenses" on the Condensed Consolidated Statement of Operations. Additionally as part of signing of the Consortium Purchase Agreement certain rebates previously issued were settled by the issuance of vested Series F Convertible Preferred Stock Warrants. The difference in fair value of these warrants over the cash settlement price is recorded in "Other Expense" on the Condensed Consolidated Statement of Operations. Commitments and Contingencies Future Minimum Lease Payments Prosper has entered into various non-cancelable operating leases for certain offices with contractual lease periods expiring between 2022 and 2027 . Future minimum rental payments under these leases as of June 30, 2017 are as follows (in thousands): Remaining six months of 2017 2,762 2018 5,690 2019 6,026 2020 6,193 2021 6,170 2022 6,076 Thereafter 8,480 Total future operating lease obligations $ 41,397 The payments in the above table include amounts that have been accrued for as part of the restructuring liability in Note 14. Restructuring accrual balances related to operating facility leases were $3.4 million at June 30, 2017 . Rental expense under operating lease arrangements was $1.2 million and $1.9 million for the three months ended June 30, 2017 and 2016 , respectively. Rental expense under operating lease arrangements was $2.5 million and $3.7 million for the six months ended June 30, 2017 and 2016 , respectively. Operating Commitments Prosper has entered into an agreement with WebBank, under which all Borrower Loans originated through the marketplace are made by WebBank under its bank charter. Pursuant to the agreement, the marketing fee that Prosper receives in connection with the origination of each loan is partially reduced by an amount (the “Designated Amount”) calculated as a percentage of the principal amount of such loan based on the aggregate principal amount of loans originated for the applicable month. To the extent the aggregate Designated Amount for all loans originated during any month is less than $143,500 , Prosper is required to pay WebBank an amount equal to such deficiency. Accordingly, t he minimum fee for the remaining nine months ended December 31, 2017 is $0.9 million . The minimum fee is $1.7 million and $0.9 million in each of the years 2018 and 2019, respectively. Additionally, under the agreement with WebBank, Prosper is required to maintain a minimum net liquidity of $15 million at all times during the term of the agreement. Net liquidity is defined as the sum of Cash, Cash Equivalents and Available for Sale Investments. Violation of this covenant can result in termination of the contract with WebBank. At June 30, 2017 , Prosper was in compliance with the covenant. Loan Purchase Commitments Prosper has entered into an agreement with WebBank to purchase $40.9 million of Borrower Loans that WebBank originated during the last two business days of the quarter ended June 30, 2017 and the first business day of the quarter ending September 30, 2017. Prosper will purchase these Borrower Loans within the first three business days of the quarter ending September 30, 2017. Repurchase and Indemnification Contingency Under the terms of the loan purchase agreements between Prosper and investors that participate in the Whole Loan Channel, Prosper may, in certain circumstances, become obligated to repurchase a Borrower Loan from an investor. Generally, these circumstances include the occurrence of verifiable identity theft, the failure to properly follow loan listing or bidding protocols, or a violation of the applicable federal, state, or local lending laws. The fair value of the indemnification and repurchase obligation is estimated based on historical experience and the initial fair value is insignificant. Prosper recognizes a liability for the repurchase and indemnification obligation when the Borrower Loans are issued. Indemnified or repurchased Borrower Loans associated with violations of federal, state, or local lending laws or verifiable identity theft are written off at the time of repurchase or at the time an indemnification payment is made. The maximum potential amount of future payments associated under this obligation is the outstanding balances of the Borrower Loans issued through the Whole Loan Channel, which at June 30, 2017 is $3,557 million . Prosper has accrued $1.1 million and $0.6 million as of June 30, 2017 and December 31, 2016 , respectively, in regard to this obligation. Securities Law Compliance From inception through October 16, 2008, Prosper sold approximately $178.0 million of Borrower Loans to investors through its old platform structure, whereby Prosper assigned promissory notes directly to investors. Prosper did not register the offer and sale of the promissory notes corresponding to these Borrower Loans under the Securities Act or under the registration or qualification provisions of any state securities laws. Prosper believes that the question of whether or not the operation of the platform during this period constituted an offer or sale of “securities” involved a complicated factual and legal analysis and was uncertain. If the sales of promissory notes offered through the platform during this period were viewed as a securities offering, Prosper would have failed to comply with the registration and qualification requirements of federal and state laws. In 2008, plaintiffs filed a class action lawsuit against Prosper and certain of its executive officers and directors in the Superior Court of California, County of San Francisco, California. The suit was brought on behalf of all promissory note purchasers on the platform from January 1, 2006 through October 14, 2008. The lawsuit alleged that Prosper offered and sold unqualified and unregistered securities in violation of the California and federal securities laws. On July 19, 2013 solely to avoid the costs, risks and uncertainties inherent in litigation, and without admitting any liability or wrongdoing, the parties to the class action litigation agreed to enter into a settlement to resolve all claims related thereto (the “Settlement”). In connection with the Settlement, Prosper agreed to pay an aggregate amount of $10 million into a settlement fund, split into four annual installments of $2 million in 2014, $2 million in 2015, $3 million in 2016 and $3 million in 2017. The Settlement received final approval in a final order and judgment entered by the Superior Court on April 16, 2014. Pursuant to the final order and judgment, the claims in the class action were dismissed, and the defendants were released by the plaintiffs from all claims that were or could have been asserted concerning the issues alleged in the class action lawsuit. All annual installments have been made prior to June 30, 2017 .
Prosper Funding LLC
Entity Information [Line Items]
Commitments and Contingencies	Commitments and Contingencies Operating Commitments Prosper has entered into an agreement with WebBank, under which all Borrower Loans originated through the marketplace are made by WebBank under its bank charter. Pursuant to the agreement, the marketing fee that Prosper receives in connection with the origination of each loan is partially reduced by an amount (the “Designated Amount”) calculated as a percentage of the principal amount of such loan based on the aggregate principal amount of loans originated for the applicable month. To the extent the aggregate Designated Amount for all loans originated during any month is less than $143,500 , Prosper is required to pay WebBank an amount equal to such deficiency. Accordingly, the minimum fee for the remaining nine months of 2017 is $1.3 million . The minimum fee is $1.7 million and $0.9 million for years 2018 and 2019 , respectively. Loan Purchase Commitments Under the terms of Prosper Funding’s agreement with WebBank, Prosper Funding is committed to purchase $40.9 million of Borrower Loans that WebBank originated during the last two business days of the quarter ended June 30, 2017 and first business day of the quarter ending September 30, 2017. Prosper Funding will purchase these Borrower Loans within the first three business days of the quarter ending September 30, 2017. Repurchase and Indemnification Contingency Under the terms of the loan purchase agreements between Prosper Funding and investors that participate in the Whole Loan Channel, Prosper Funding may, in certain circumstances, become obligated to repurchase a Borrower Loan from an investor. Generally, these circumstances include the occurrence of verifiable identity theft, the failure to properly follow loan listing or bidding protocols, or a violation of the applicable federal, state, or local lending laws. The fair value of the indemnification and repurchase obligation is estimated based on historical experience. Prosper Funding recognizes a liability for the repurchase and indemnification obligation when the Borrower Loans are issued. Indemnified or repurchased Borrower Loans associated with violations of federal, state, or local lending laws or verifiable identity theft are written off at the time of repurchase or at the time an indemnification payment is made. The maximum potential amount of future payments associated under this obligation is the outstanding balances of the Borrower Loans issued through the Whole Loan Channel, which at June 30, 2017 is $3,506 million . Prosper Funding had accrued $1.0 million and $0.6 million as of June 30, 2017 and December 31, 2016 , respectively, in regard to this obligation.

Related Parties

Related Parties	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Related Parties	Related Parties Since Prosper’s inception, it has engaged in various transactions with its directors, executive officers and holders of more than 10% of its voting securities, and immediate family members and other affiliates of its directors, executive officers and 10% stockholders. Prosper believes that all of the transactions described below were made on terms no less favorable to Prosper than could have been obtained from unaffiliated third parties. Prosper’s executive officers, directors who are not executive officers, and certain affiliates participate in its marketplace by placing bids and purchasing Notes and Borrower Loans. The aggregate amount of the Notes and Borrower Loans purchased and the income earned by parties deemed to be affiliates and related parties of Prosper for the six months ended June 30, 2017 and 2016 , as well as the Notes and Borrower Loans outstanding as of June 30, 2017 and December 31, 2016 are summarized below (in thousands): Aggregate Amount of Notes and Borrower Loans Purchased Six Months Ended June 30, Interest Earned on Notes and Borrower Loans Six Months Ended June 30, Related Party 2017 2016 2017 2016 Executive officers and management $ 10 $ 801 $ 81 $ 110 Directors (excluding executive officers and management) 174 350 20 15 Total $ 184 $ 1,151 $ 101 $ 125 Aggregate Amount of Notes and Borrower Loans Purchased Three Months Ended June 30, Interest Earned on Notes and Borrower Loans Three Months Ended June 30, Related Party 2017 2016 2017 2016 Executive officers and management $ 5 $ 396 $ 35 $ 61 Directors (excluding executive officers and management) 85 114 10 9 Total $ 90 $ 510 $ 45 $ 70 Notes and Borrower Loans Balance as of Related Party June 30, 2017 December 31, 2016 Executive officers and management $ 1,012 $ 1,620 Directors (excluding executive officers and management) 560 537 $ 1,572 $ 2,157
Prosper Funding LLC
Entity Information [Line Items]
Related Parties	Related Parties Since inception, Prosper Funding has engaged in various transactions with its directors, executive officers and sole member, and immediate family members and other affiliates of its directors, executive officers and sole member. Prosper Funding believes that all of the transactions described below were made on terms no less favorable to Prosper Funding than could have been obtained from unaffiliated third parties. Prosper Funding’s executive officers and directors who are not executive officers participate in its marketplace by placing bids and purchasing Notes and Borrower Loans. The aggregate amount of the Notes and Borrower Loans purchased and the income earned by parties deemed to be related parties of Prosper Funding as of June 30, 2017 and December 31, 2016 are summarized below (in thousands): Aggregate Amount of Notes and Borrower Loans Purchased Six Months Ended June 30, Interest Earned on Notes and Borrower Loans Six Months Ended June 30, Related Party 2017 2016 2017 2016 Executive officers and management $ 10 $ 801 $ 81 $ 110 Directors (excluding executive officers and management) — — — — Total $ 10 $ 801 $ 81 $ 110 Aggregate Amount of Notes and Borrower Loans Purchased Interest Earned on Notes and Borrower Loans Three Months Ended June 30, Three Months Ended June 30, Related Party 2017 2016 2017 2016 Executive officers and management $ 5 $ 396 $ 35 $ 61 Directors (excluding executive officers and management) — — — — Total $ 5 $ 396 $ 35 $ 61 Note and Borrower Loan Balance as of Related Party June 30, 2017 December 31, 2016 Executive officers and management $ 1,012 $ 1,620 Directors (excluding executive officers and management) — — $ 1,012 $ 1,620

Significant Concentrations

Significant Concentrations	6 Months Ended
	Jun. 30, 2017
Risks and Uncertainties [Abstract]
Significant Concentrations	Significant Concentrations Prosper is dependent on third party funding sources such as banks and investment funds to provide the funds to allow WebBank to originate Borrower Loans that the third party funding sources will later purchase. Of all Borrower Loans originated in the six months ended June 30, 2017, 52% , 14% and 8% were purchased by three different parties. This compares to 25% , 25% and 12% for the period ended June 30, 2016. Further, a significant portion of our business is dependent on funding through the Whole Loan Channel, for which 92% and 92% of Borrower Loans were originated through the Whole Loan Channel in the six months ended June 30, 2017 and 2016, respectively. Prosper receives all of its transaction fee revenue from WebBank. Prosper earns a transaction fee from WebBank for our services in facilitating originations of Borrower Loans issued by WebBank. The rate of the transaction fee for each individual Borrower Loan is based on the term and credit grade of the Borrower Loan. No individual borrower or investor accounted for 10% or more of consolidated net revenue for any of the periods presented.

Summary of Significant Accoun27

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Basis of Presentation	Basis of Presentation Prosper Marketplace, Inc. (“PMI”) was incorporated in the state of Delaware on March 22, 2005. Except as the context requires otherwise, as used in these notes to the condensed consolidated financial statements of Prosper Marketplace, Inc., “Prosper,” “we,” “us,” and “our” refer to PMI and its wholly-owned subsidiaries, on a consolidated basis. The unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“US GAAP”) and disclosure requirements for interim financial information and the requirements of Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements. The unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2016 . The balance sheet at December 31, 2016 has been derived from the audited financial statements at that date. Management believes these unaudited interim condensed consolidated financial statements reflect all adjustments, consisting of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. The preparation of Prosper’s condensed consolidated financial statements and related disclosures in conformity with GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in Prosper’s financial statements and accompanying notes. Management bases its estimates on historical experience and on various other factors it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of certain assets and liabilities. These judgments, estimates and assumptions are inherently subjective in nature and actual results may differ from these estimates and assumptions. The accompanying interim condensed consolidated financial statements include the accounts of PMI and its wholly-owned subsidiaries. All intercompany balances have been eliminated in consolidation.
Fair Value Measurements	Fair Value Measurements Financial instruments consist principally of Cash and Cash Equivalents, Restricted Cash, Available for Sale Investments at Fair Value, Borrower Loans, Loans Held for Sale, Accounts Receivable, Accounts Payable and Accrued Liabilities, Payable to Investors, Convertible Preferred Stock Warrant Liability and Notes. The estimated fair values of Cash and Cash Equivalents, Restricted Cash, Accounts Receivable, Accounts Payable and Accrued Liabilities, and Payable to Investors approximate their carrying values because of their short term nature.
Borrower Loans, Loans Held for Sale and Notes	Borrower Loans, Loans Held for Sale and Notes Through the Note Channel, Prosper purchases Borrower Loans from WebBank then issues Notes, and holds the Borrower Loans until maturity. The obligation to repay a series of Notes issued through the Note Channel is dependent upon the repayment of the associated Borrower Loan. Borrower Loans funded and Notes issued through the Note Channel are carried on Prosper’s condensed consolidated balance sheets as assets and liabilities, respectively. We choose to measure certain financial instruments and certain other items at fair value on an instrument-by-instrument basis with unrealized gains and losses on items for which the fair value option has been elected reported in earnings. Management believes that the fair value option is more meaningful for the readers of the financial statements and it allows both the Borrower Loans and Notes to be valued using the same methodology. The fair value election, with respect to an item, may not be revoked once an election is made. Prosper estimates the fair value of such Borrower Loans and Notes using discounted cash flow methodologies that take into account expected prepayments, losses, recoveries and default rates. The Borrower Loans are not derecognized when a corresponding Note is issued as Prosper maintains the ability to sell the Borrower Loans without the approval of the holders of the corresponding Notes.
Assets Held for Sale	Assets Held for Sale: Prosper classifies assets as held for sale when management approves and commits to a formal plan of sale with the expectation the sale will be completed within one year. The net assets held for sale are then recorded at the lower of their current carrying value or the fair market value, less costs to sell.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, as part of its ongoing efforts to assist in the convergence of US GAAP and International Financial Reporting Standards (“IFRS”), the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “ Revenue from Contracts with Customers .” The new guidance sets forth a new five-step revenue recognition model which replaces the prior revenue recognition guidance in its entirety and is intended to eliminate numerous industry-specific pieces of revenue recognition guidance that have historically existed in U.S. GAAP. The underlying principle of the new standard is that a business or other organization will recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects what it expects in exchange for the goods or services. The standard also requires more detailed disclosures and provides additional guidance for transactions that were not addressed completely in the prior accounting guidance. The standard will be effective for Prosper in the first quarter of fiscal 2018. In August 2015, the FASB issued ASU No. 2015-14, which amended the standard to provide a one-year deferral of the effective date, as well as providing the option to early adopt the standard on the original effective date. Prosper intends to adopt the guidance for Prosper's fiscal year ending December 31, 2018. The guidance can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Prosper expects to adopt this ASU on a modified retrospective basis in the first quarter of fiscal 2018. Our preliminary results indicate that transaction fees are included in the scope of the new guidance, while servicing fees and gain or loss on the sale of loans remain within the scope of ASC topic 860, Transfers and Servicing. While we anticipate some changes to revenue recognition for certain customer contracts, Prosper does not currently believe that this ASU will have a material effect on our Consolidated Financial Statements. In January 2016, the FASB issued ASU 2016-1, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities" , which addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. This guidance will be effective for us in the first quarter of our fiscal year 2019, and early adoption is not permitted. Prosper is currently evaluating the impact that this guidance will have on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , which requires an entity to recognize assets and liabilities arising from a lease for both financing and operating leases, along with additional qualitative and quantitative disclosures. This guidance will be effective for us in the first quarter of our fiscal year 2019, and early adoption is permitted. Prosper is currently evaluating the impact that this guidance will have on its consolidated financial statements, however we do expect that this guidance will have a material impact on Prosper's consolidated financial statements. As of June 30, 2017 Prosper has a total of $41.4 million in non-cancelable operating lease commitments. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” The standard provides guidance for eight targeted changes with respect to how cash receipts and cash payments are classified in the statements of cash flows, with the objective of reducing diversity in practice. This guidance will be effective for Prosper in the first quarter of our fiscal year 2018, and early adoption is permitted. Prosper is currently evaluating the impacts the adoption of this accounting standard will have on Prosper's consolidated financial statements. In October 2016, the FASB issued ASU No. 2016-16, " Income Taxes (Topic 740): Intra-Entity Transfers Other than Inventory (ASU 2016-16)" , which requires companies to recognize the income-tax consequences of an intra-entity transfer of an asset other than inventory. This guidance will be effective for us in the first quarter of 2018, with the option to adopt it in the first quarter of 2017. Prosper is currently evaluating the impact that this guidance will have on its consolidated financial statements, however we do not believe the standard to have a material impact on our consolidated financial statements. In November 2016, the FASB issued ASU 2016-18, " Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18)" , which requires companies to include amounts generally described as restricted cash and restricted cash equivalents in cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance will be effective for us in the first quarter of 2018 and early adoption is permitted. Prosper is currently evaluating the effect that this guidance will have on our consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment ". The standard eliminates Step 2 from the goodwill impairment test, which requires a hypothetical purchase price allocation. Prosper will continue to have the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. The standard is effective for interim and annual periods beginning after December 15, 2019 and early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The standard should be applied on a prospective basis. Prosper is currently evaluating the impact of this accounting standard update on its consolidated financial statements.
Prosper Funding LLC
Entity Information [Line Items]
Basis of Presentation	Basis of Presentation Prosper Funding LLC (“PFL”) was formed in the state of Delaware on February 17, 2012 as a limited liability company with the sole equity member being Prosper Marketplace, Inc. (“PMI”, "Parent"). Except as the context otherwise requires, as used in these Notes to the condensed consolidated financial statements of Prosper Funding LLC, “Prosper Funding,” “we,” “us,” and “our” refers to PFL and its wholly owned subsidiaries, Prosper Asset Holdings LLC (“PAH”), a Delaware limited liability company, and Prosper Depositor LLC, a Delaware limited liability company, on a consolidated basis. The unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“US GAAP”) and disclosure requirements for interim financial information and the requirements of Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements. The unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2016 . The balance sheet at December 31, 2016 has been derived from the audited financial statements at that date. Management believes these unaudited interim condensed consolidated financial statements reflect all adjustments, consisting of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. Prosper Funding did no t have any items of other comprehensive income (loss) during any of the periods presented in the condensed consolidated financial statements as of and for the six months ended June 30, 2017 and June 30, 2016 . The preparation of Prosper Funding's condensed consolidated financial statements and related disclosures in conformity with GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in its condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on various other factors it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of certain assets and liabilities. These judgments, estimates and assumptions are inherently subjective in nature and actual results may differ from these estimates and assumptions, and the differences could be material.
Fair Value Measurements	Fair Value Measurements Financial instruments consist principally of Cash and Cash Equivalents, Restricted Cash, Short Term Investments, Borrower Loans, Loans Held for Sale, Accounts Receivable, Accounts Payable and Accrued Liabilities, Payable to Investors and Notes. The estimated fair values of Cash and Cash Equivalents, Restricted Cash, Accounts Receivable, Accounts Payable and Accrued Liabilities, and Payable to Investors approximate their carrying values because of their short term nature.
Borrower Loans, Loans Held for Sale and Notes	Borrower Loans, Loans Held for Sale and Notes Through the Note Channel, Prosper Funding purchases Borrower Loans from WebBank then issues Notes, and holds the Borrower Loans until maturity. The obligation to repay a series of Notes funded through the Note Channel is dependent upon the repayment of the associated Borrower Loan. Borrower Loans and Notes funded through the Note Channel are carried on Prosper Funding’s consolidated balance sheets as assets and liabilities, respectively. We choose to measure certain financial instruments and certain other items at fair value on an instrument-by-instrument basis with unrealized gains and losses on items for which the fair value option has been elected reported in earnings. Management believes that the fair value option is more meaningful for the readers of the financial statements and it allows both the Borrower Loans and Notes to be valued using the same methodology. The fair value election, with respect to an item, may not be revoked once an election is made. Prosper Funding estimates the fair value of such Borrower Loans and Notes using discounted cash flow methodologies that take into account expected prepayments, losses, recoveries and default rates. The Borrower Loans are not derecognized when a corresponding Note is issued as Prosper Funding maintains the ability to sell the Borrower Loans without the approval of the holders of the corresponding Notes.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, as part of its ongoing efforts to assist in the convergence of US GAAP and International Financial Reporting Standards (“IFRS”), the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers.” The new guidance sets forth a new five-step revenue recognition model which replaces the prior revenue recognition guidance in its entirety and is intended to eliminate numerous industry-specific pieces of revenue recognition guidance that have historically existed in U.S. GAAP. The underlying principle of the new standard is that a business or other organization will recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects what it expects in exchange for the goods or services. The standard also requires more detailed disclosures and provides additional guidance for transactions that were not addressed completely in the prior accounting guidance. The standard will be effective for Prosper Funding in the first quarter of fiscal 2018. In August 2015, the FASB issued ASU No. 2015-14, which amended the standard to provide a one-year deferral of the effective date, as well as providing the option to early adopt the standard on the original effective date. The guidance can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Prosper Funding expects to adopt this ASU on a modified retrospective basis in the first quarter of fiscal 2018. Our evaluation of this ASU is ongoing and not complete. The FASB has issued and may issue in the future, interpretative guidance, which may cause our evaluation to change. Our preliminary results indicate that administration fees are included in the scope of the new guidance, while servicing fees and gain or loss on the sale of loans remain within the scope of ASC topic 860, Transfers and Servicing. Prosper Funding does not currently believe that this ASU will have a material effect on our Consolidated Financial Statements. In January 2016, the FASB issued ASU 2016-1, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities" , which addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. This guidance will be effective for us in the first quarter of our fiscal year 2019, and early adoption is not permitted. Prosper Funding is currently evaluating the impact that this guidance will have on our consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” The standard provides guidance for eight targeted changes with respect to how cash receipts and cash payments are classified in the statements of cash flows, with the objective of reducing diversity in practice. This guidance will be effective for Prosper Funding in the first quarter of our fiscal year 2018, and early adoption is permitted. Prosper Funding is currently evaluating the impacts the adoption of this accounting standard will have on the Prosper Funding's cash flows. In November 2016, the FASB issued ASU 2016-18, "Statement of Cash Flows (Topic 230): Restricted Cash (ASU2016-18)", which requires companies to include amounts generally described as restricted cash and restricted cash equivalents in cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance will be effective for us in the first quarter of 2018 and early adoption is permitted. Prosper Funding is currently evaluating the effect that this guidance will have on our consolidated financial statements and related disclosures.

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Property and Equipment, Net	Property and equipment consist of the following (in thousands): June 30, December 31, Property and equipment: Computer equipment $ 14,370 $ 14,107 Internal-use software and website development costs 18,603 16,750 Office equipment and furniture 3,010 3,010 Leasehold improvements 7,038 7,038 Assets not yet placed in service 1,453 1,222 Property and equipment 44,474 42,127 Less accumulated depreciation and amortization (22,406 ) (17,274 ) Total property and equipment, net $ 22,068 $ 24,853
Prosper Funding LLC
Entity Information [Line Items]
Property and Equipment, Net	Property and equipment consist of the following (in thousands): June 30, December 31, Property and equipment: Internal-use software and web site development costs $ 18,603 $ 16,749 Less accumulated depreciation and amortization (9,291 ) (6,654 ) Total property and equipment, net $ 9,312 $ 10,095

Borrower Loans, Loans Held fo29

Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value (Tables)	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Aggregate Principal Balances Outstanding and Fair Values of Borrower Loans, Notes and Loans Held for Sale	The aggregate principal balances outstanding and fair values of Borrower Loans, Loans Held for Sale and Notes as of June 30, 2017 and December 31, 2016 , are presented in the following table (in thousands): Borrower Loans Notes Loans Held for Sale June 30, December 31, June 30, December 31, June 30, December 31, Aggregate principal balance outstanding $ 316,378 $ 319,143 $ (319,072 ) $ (323,358 ) $ 106 $ 641 Fair value adjustments (4,106 ) (3,516 ) 7,662 7,122 (11 ) (17 ) Fair value $ 312,272 $ 315,627 $ (311,410 ) $ (316,236 ) $ 95 $ 624
Prosper Funding LLC
Entity Information [Line Items]
Aggregate Principal Balances Outstanding and Fair Values of Borrower Loans, Notes and Loans Held for Sale	The aggregate principal balances outstanding and fair values of Borrower Loans, Loans Held for Sale and Notes as of June 30, 2017 and December 31, 2016 , are presented in the following table (in thousands): Borrower Loans Notes Loans Held for Sale June 30, 2017 December 31, 2016 June 30, 2017 December 31, 2016 June 30, 2017 December 31, 2016 Aggregate principal balance outstanding $ 316,378 $ 319,143 $ (319,072 ) $ (323,358 ) $ 106 $ 641 Fair value adjustments (4,106 ) (3,516 ) 7,662 7,122 (11 ) (17 ) Fair value $ 312,272 $ 315,627 $ (311,410 ) $ (316,236 ) $ 95 $ 624

Available for Sale Investment30

Available for Sale Investments, at Fair Value (Tables)	6 Months Ended
	Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Securities Available for Sale	The amortized cost, gross unrealized gains and losses, and fair value of available for sale investments as of June 30, 2017 and December 31, 2016 , are as follows (in thousands): June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity securities: US Treasury securities 5,501 — (3 ) 5,498 Agency bonds 2,500 — (1 ) 2,499 Total Available for Sale Investments $ 8,001 $ — $ (4 ) $ 7,997 December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Fixed maturity securities: Corporate debt securities $ 21,762 $ 1 $ (10 ) $ 21,753 US Treasury securities 8,516 3 (3 ) 8,516 Agency bonds 2,499 1 — 2,500 Total Available for Sale Investments $ 32,777 $ 5 $ (13 ) $ 32,769
Summary of Securities Available for Sale of Continuous Unrealized Loss	A summary of available for sale investments with unrealized losses as of June 30, 2017 , and December 31, 2016 , aggregated by category and period of continuous unrealized loss, is as follows (in thousands): Less than 12 months 12 months or longer Total June 30, 2017 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed maturity securities: U.S. treasury securities $ 5,498 $ (3 ) $ 5,498 $ (3 ) Agency bonds — — 2,499 (1 ) 2,499 (1 ) Total Investments with Unrealized Losses $ 5,498 $ (3 ) $ 2,499 $ (1 ) $ 7,997 $ (4 ) Less than 12 months 12 months or longer Total December 31, 2016 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed maturity securities: Corporate debt securities $ — $ — $ 14,651 $ (10 ) $ 14,651 $ (10 ) U.S. treasury securities $ — $ — $ 4,499 $ (3 ) $ 4,499 $ (3 ) Total Investments with Unrealized Losses $ — $ — $ 19,150 $ (13 ) $ 19,150 $ (13 )
Schedule of Maturities of Securities Available for Sale	The maturities of available for sale investments at June 30, 2017 and December 31, 2016 are as follows (in thousands): June 30, 2017 Within 1 year After 1 year through 5 years After 5 years to 10 years After 10 years Total US Treasury securities 5,498 5,498 Agency bonds 2,499 2,499 Total Fair Value $ 7,997 $ — $ — $ — $ 7,997 Total Amortized Cost $ 8,001 $ — $ — $ — $ 8,001 December 31, 2016 Within 1 year After 1 year through 5 years After 5 years to 10 years After 10 years Total Corporate debt securities 21,753 — — — 21,753 US Treasury securities 8,516 — — — 8,516 Agency bonds 2,500 — — — 2,500 Total Fair Value $ 32,769 $ — $ — $ — $ 32,769 Total Amortized Cost $ 32,777 $ — $ — $ — $ 32,777

Fair Value of Assets and Liab31

Fair Value of Assets and Liabilities (Tables)	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value	The following tables present the fair value hierarchy for assets and liabilities measured at fair value (in thousands): June 30, 2017 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 312,272 $ 312,272 Loans Held for Sale — — 95 95 Available for Sale Investments, at Fair Value — 7,997 — 7,997 Servicing Assets — — 13,489 13,489 Total Assets — 7,997 325,856 333,853 Liabilities: Notes $ — $ — $ 311,410 $ 311,410 Servicing Liabilities — — 111 111 Convertible Preferred Stock Warrant Liability — — 70,114 70,114 Loan Trailing Fee Liability — — 1,655 1,655 Total Liabilities $ — $ — $ 383,290 $ 383,290 December 31, 2016 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 315,627 $ 315,627 Loans Held for Sale — — 624 624 Available for Sale Investments, at Fair Value — 32,769 — 32,769 Servicing Assets — — 12,786 12,786 Total Assets — 32,769 329,037 361,806 Liabilities: Notes $ — $ — $ 316,236 $ 316,236 Servicing Liabilities — — 198 198 Convertible Preferred Stock Warrant Liability — — 21,711 21,711 Loan Trailing Fee Liability — — 665 665 Total Liabilities $ — $ — $ 338,810 $ 338,810
Quantitative Information About Significant Unobservable Inputs	Borrower Loans, Loans Held for Sale and Notes: Range Unobservable Input June 30, 2017 December 31, 2016 Discount rate 4.3% - 15.2% 4.0% - 15.9% Default rate 1.9% - 15.2% 1.7% - 14.9%
Significant Unobservable Inputs Fair Value	Servicing Rights Range Unobservable Input June 30, 2017 December 31, 2016 Discount rate 15% - 25% 15% - 25% Default rate 1.6% - 15.7% 1.5% - 15.2% Prepayment rate 14.4% - 26.7% 13.6% - 26.6% Market servicing rate 0.625 % 0.625 %
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present additional information about level 3 Borrower Loans, Loans Held for Sale and Notes measured at fair value on a recurring basis (in thousands): Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at January 1, 2017 $ 315,627 $ (316,236 ) $ 624 $ 15 Purchase of Borrower Loans/Issuance of Notes 106,940 (106,506 ) 1,245,826 1,246,260 Principal repayments (97,492 ) 100,274 (42 ) 2,740 Borrower Loans sold to third parties (1,990 ) — (1,246,316 ) (1,248,306 ) Other changes 9 266 (3 ) 272 Change in fair value (10,822 ) 10,792 6 (24 ) Balance at June 30, 2017 $ 312,272 $ (311,410 ) $ 95 $ 957 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at January 1, 2016 $ 297,273 $ (297,405 ) $ 32 $ (100 ) Purchase of Borrower Loans/Issuance of Notes 109,215 (109,147 ) 1,358,011 1,358,079 Principal repayments (82,376 ) 83,119 (136 ) 607 Borrower Loans sold to third parties (1,138 ) 1,081 (1,353,202 ) (1,353,259 ) Other changes (6 ) (33 ) — (39 ) Change in fair value (12,934 ) 12,855 — (79 ) Balance at June 30, 2016 $ 310,034 $ (309,530 ) $ 4,705 $ 5,209 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at April 1, 2017 $ 317,536 $ (316,944 ) $ 109 $ 701 Purchase of Borrower Loans/Issuance of Notes 50,260 (49,692 ) 721,829 722,397 Principal repayments (48,048 ) 48,695 (14 ) 633 Borrower Loans sold to third parties (869 ) — (721,829 ) (722,698 ) Other changes 10 (156 ) — (146 ) Change in fair value (6,617 ) 6,687 — 70 Balance at June 30, 2017 $ 312,272 $ (311,410 ) $ 95 $ 957 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at April 1, 2016 $ 303,243 $ (302,357 ) $ 30 $ 916 Purchase of Borrower Loans/Issuance of Notes 54,044 (53,873 ) 426,591 426,762 Principal repayments (41,390 ) 41,057 (131 ) (464 ) Borrower Loans sold to third parties (525 ) 499 (421,784 ) (421,810 ) Other changes (2 ) (191 ) — (193 ) Change in fair value (5,336 ) 5,335 (1 ) (2 ) Balance at June 30, 2016 $ 310,034 $ (309,530 ) $ 4,705 $ 5,209
Schedule of Servicing Assets and Liabilities Measured at Fair Value	The following tables present additional information about level 3 servicing assets and liabilities measured at fair value on a recurring basis (in thousands): Servicing Assets Servicing Liabilities Fair Value at January 1, 2017 12,786 198 Additions 6,532 — Less: Changes in fair value (5,829 ) (87 ) Fair Value at June 30, 2017 13,489 111 Servicing Assets Servicing Liabilities Fair Value at January 1, 2016 14,363 484 Additions 5,750 9 Less: Changes in fair value (5,816 ) (169 ) Fair Value at June 30, 2016 14,297 324 Servicing Assets Servicing Liabilities Fair Value at April 1, 2017 12,436 147 Additions 3,768 — Less: Changes in fair value (2,715 ) (36 ) Fair Value at June 30, 2017 13,489 111 Servicing Assets Servicing Liabilities Fair Value at April 1, 2016 15,548 398 Additions 1,729 — Less: Changes in fair value (2,980 ) (74 ) Fair Value at June 30, 2016 14,297 324 The following table presents additional information about level 3 Loan Trailing Fee Liability measured at fair value on a recurring basis (in thousands): Balance at January 1, 2017 665 Issuances 1,216 Cash payment of Loan Trailing Fee (351 ) Change in fair value 125 Balance at June 30, 2017 1,655
Fair Value Assumptions for Loans Held for Sale, Borrower Loans and Notes	Key economic assumptions and the sensitivity of the current fair value to immediate changes in those assumptions at June 30, 2017 for Borrower Loans, Loans Held for Sale and Notes funded through the Note Channel are presented in the following table (in thousands, except percentages): Borrower Loans and Loans Held for Sale Notes Discount rate assumption: 7.55 % * 7.55 % * Resulting fair value from: 100 basis point increase $ 309,203 $ 308,250 200 basis point increase 306,119 305,170 Resulting fair value from: 100 basis point decrease $ 315,614 $ 314,653 200 basis point decrease 318,948 317,984 Default rate assumption: 12.96 % * 12.96 % * Resulting fair value from: 100 basis point increase $ 308,608 $ 307,645 200 basis point increase 304,984 304,015 Resulting fair value from: 100 basis point decrease $ 316,150 $ 315,200 200 basis point decrease 319,980 319,038 * Represents weighted average assumptions considering all credit grades.
Schedule of Prosper's and Prosper Funding's Estimated Fair Value of Servicing Assets and Liabilities	The following table presents the estimated impact on Prosper’s estimated fair value of servicing assets and liabilities, calculated using different market servicing rates and different default rates as of June 30, 2017 (in thousands, except percentages). Servicing Assets Servicing Liabilities Market servicing rate assumptions 0.625 % 0.625 % Resulting fair value from: Market servicing rate increase to 0.65% $ 12,613 $ 122 Market servicing rate decrease to 0.60% $ 14,365 $ 100 Weighted average prepayment assumptions 20.09 % 20.09 % Resulting fair value from: Applying a 1.1 multiplier to prepayment rate $ 13,301 $ 109 Applying a 0.9 multiplier to prepayment rate $ 13,678 $ 113 Weighted average default assumptions 12.18 % 12.18 % Resulting fair value from: Applying a 1.1 multiplier to default rate $ 13,301 $ 111 Applying a 0.9 multiplier to default rate $ 13,680 $ 111
Prosper Funding LLC
Entity Information [Line Items]
Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value	The following tables present the fair value hierarchy for assets and liabilities measured at fair value (in thousands): June 30, 2017 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 312,272 $ 312,272 Servicing Assets — — 13,297 13,297 Loans Held for Sale — — 95 95 Total Assets — — 325,664 325,664 Liabilities: Notes $ — $ — $ 311,410 $ 311,410 Servicing Liabilities — — 111 111 Loan Trailing Fee Liability 1,655 1,655 Total Liabilities $ — $ — $ 313,176 $ 313,176 December 31, 2016 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 315,627 $ 315,627 Servicing Assets — — 12,461 12,461 Loans Held for Sale — — 624 624 Total Assets — — 328,712 328,712 Liabilities: Notes $ — $ — $ 316,236 $ 316,236 Servicing Liabilities — — 198 198 Loan Trailing Fee Liability — — 665 665 Total Liabilities $ — $ — $ 317,099 $ 317,099
Quantitative Information About Significant Unobservable Inputs	The following tables present quantitative information about the significant unobservable inputs used for Prosper Funding’s level 3 fair value measurements at June 30, 2017 and December 31, 2016 : Borrower Loans, Loans Held for Sale and Notes: Range Unobservable Input June 30, 2017 December 31, 2016 Discount rate 4.3% - 15.2% 4.0% - 15.9% Default rate 1.9% - 15.2% 1.7% - 14.9%
Significant Unobservable Inputs Fair Value	Servicing Rights Range Unobservable Input June 30, 2017 December 31, 2016 Discount rate 15% - 25% 15% - 25% Default rate 1.6% - 15.7% 1.5% - 15.2% Prepayment rate 14.4% - 26.7% 13.6% - 26.6% Market servicing rate 0.625 % 0.625 %
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The changes in the Borrower Loans, Loans Held for Sale and Notes, which are Level 3 assets and liabilities measured at fair value on a recurring basis are as follows (in thousands): Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at January 1, 2017 $ 315,627 $ (316,236 ) $ 624 $ 15 Originations 106,940 (106,506 ) 1,245,826 1,246,260 Principal repayments (97,492 ) 100,274 (42 ) 2,740 Borrower Loans sold to third parties (1,990 ) — (1,246,316 ) (1,248,306 ) Other changes 9 266 (3 ) 272 Change in fair value (10,822 ) 10,792 6 (24 ) Balance at June 30, 2017 $ 312,272 $ (311,410 ) $ 95 $ 957 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at January 1, 2016 $ 297,273 $ (297,405 ) $ 32 $ (100 ) Originations 109,215 (109,147 ) 1,358,011 1,358,079 Principal repayments (82,376 ) 83,119 (136 ) 607 Borrower Loans sold to third parties (1,138 ) 1,081 (1,353,202 ) (1,353,259 ) Other changes (6 ) (33 ) — (39 ) Change in fair value (12,934 ) 12,855 — (79 ) Balance at June 30, 2016 $ 310,034 $ (309,530 ) $ 4,705 $ 5,209 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at April 1, 2017 $ 317,536 $ (316,944 ) $ 109 $ 701 Originations 50,260 (49,692 ) 721,829 722,397 Principal repayments (48,048 ) 48,695 (14 ) 633 Borrower Loans sold to third parties (869 ) — (721,829 ) (722,698 ) Other changes 10 (156 ) — (146 ) Change in fair value (6,617 ) 6,687 — 70 Balance at June 30, 2017 $ 312,272 $ (311,410 ) $ 95 $ 957 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Borrower Loans Notes Loans Held for Sale Total Balance at April 1, 2016 $ 303,243 $ (302,357 ) $ 30 $ 916 Originations 54,044 (53,873 ) 426,591 426,762 Principal repayments (41,390 ) 41,057 (131 ) (464 ) Borrower Loans sold to third parties (525 ) 499 (421,784 ) (421,810 ) Other changes (2 ) (191 ) — (193 ) Change in fair value (5,336 ) 5,335 (1 ) (2 ) Balance at June 30, 2016 $ 310,034 $ (309,530 ) $ 4,705 $ 5,209
Schedule of Servicing Assets and Liabilities Measured at Fair Value	The following table presents additional information about Level 3 servicing assets and liabilities recorded at fair value for the three months ended June 30, 2017 (in thousands). Servicing Assets Servicing Liabilities Fair Value at January 1, 2017 12,461 198 Additions 6,532 — Less: Changes in fair value (5,696 ) (87 ) Fair Value at June 30, 2017 13,297 111 Servicing Assets Servicing Liabilities Fair Value at January 1, 2016 13,605 484 Additions 5,750 9 Less: Changes in fair value (5,557 ) (169 ) Fair Value at June 30, 2016 13,798 324 Servicing Assets Servicing Liabilities Fair Value at April 1, 2017 12,190 147 Additions 3,768 — Less: Changes in fair value (2,661 ) (36 ) Fair Value at June 30, 2017 13,297 111 Servicing Assets Servicing Liabilities Fair Value at April 1, 2016 14,929 398 Additions 1,729 — Less: Changes in fair value (2,860 ) (74 ) Fair Value at June 30, 2016 13,798 324 The following table presents additional information about level 3 Loan Trailing Fee Liability measured at fair value on a recurring basis (in thousands): Balance at January 1, 2017 665 Issuances 1,216 Cash payment of Loan Trailing Fee (351 ) Change in fair value 125 Balance at June 30, 2017 1,655
Fair Value Assumptions for Loans Held for Sale, Borrower Loans and Notes	Key economic assumptions and the sensitivity of the current fair value to immediate changes in those assumptions at June 30, 2017 for Borrower Loans, Loans Held for Sale and Notes funded are presented in the following table (in thousands, except percentages): Borrower Loans and Loans Held for Sale Notes Discount rate assumption: 7.55 % * 7.55 % * Resulting fair value from: 100 basis point increase $ 309,203 $ 308,250 200 basis point increase 306,119 305,170 Resulting fair value from: 100 basis point decrease $ 315,614 $ 314,653 200 basis point decrease 318,948 317,984 Default rate assumption: 12.96 % * 12.96 % * Resulting fair value from: 100 basis point increase $ 308,608 $ 307,645 200 basis point increase 304,984 304,015 Resulting fair value from: 100 basis point decrease $ 316,150 $ 315,200 200 basis point decrease 319,980 319,038 * Represents weighted average assumptions considering all credit grades.
Schedule of Prosper's and Prosper Funding's Estimated Fair Value of Servicing Assets and Liabilities	The following table presents the estimated impact on Prosper Funding’s estimated fair value of servicing assets and liabilities, calculated using different market servicing rates and different default rates as of June 30, 2017 (in thousands, except percentages). Servicing Assets Servicing Liabilities Market servicing rate assumptions 0.625 % 0.625 % Resulting fair value from: Market servicing rate increase to 0.65% 12,434 122 Market servicing rate decrease to 0.60% 14,160 100 Weighted average prepayment assumptions 20.09 % 20.09 % Resulting fair value from: Applying a 1.1 multiplier to prepayment rate 13,112 109 Applying a 0.9 multiplier to prepayment rate 13,484 113 Weighted average default assumptions 12.18 % 12.18 % Resulting fair value from: Applying a 1.1 multiplier to default rate 13,112 111 Applying a 0.9 multiplier to default rate 13,486 111

Goodwill and Other Intangible32

Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Other Intangible Assets for the Period Presented	The following table presents the detail of other intangible assets for the period presented (dollars in thousands): June 30, 2017 Gross Carrying Value Accumulated Amortization Net Carrying Value Remaining Useful Life (In Years) User base and customer relationships $ 4,122 $ (3,775 ) $ 347 7.8 Developed technology 4,793 (3,278 ) $ 1,515 0.8 Brand name 60 (60 ) — — Total intangible assets subject to amortization $ 8,975 $ (7,113 ) $ 1,862
Summary of Estimated Amortization of Purchased Intangible Assets	Estimated amortization of purchased intangible assets for future periods (excluding those held for sale) is as follows (in thousands): Year Ending December 31, Remainder of 2017 $ 355 2018 379 2019 279 2020 219 2021 500 Total $ 1,732

Assets Held for Sale (Tables)

Assets Held for Sale (Tables)	6 Months Ended
	Jun. 30, 2017
Assets Held-for-Sale [Abstract]
Disclosure of Long Lived Assets Held-for-sale	Amounts classified as assets held for sale on June 30, 2017, are presented on the Company’s Condensed Consolidated Balance Sheet within their respective accounts, and include the following (in thousands): Intangible Assets $ 130 Goodwill 12 Total Assets Held for Sale $ 142

Other Liabilities (Tables)

Other Liabilities (Tables)	6 Months Ended
	Jun. 30, 2017
Other Liabilities [Abstract]
Schedule of Other Liabilities	Other Liabilities includes the following: June 30, 2017 December 31, 2016 Class action settlement liability $ — $ 2,996 Repurchase liability for unvested restricted stock awards 24 118 Loan trailing fee 1,655 665 Servicing liabilities 111 198 Deferred rent 4,133 4,469 Restructuring liability 3,414 6,052 Other 3,438 2,675 Total Other Liabilities $ 12,775 $ 17,173

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Share	Basic and diluted net loss per share was calculated as follows: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Numerator: Net loss available to common stockholders for basic and diluted EPS $ (41,405 ) $ (35,628 ) $ (65,426 ) $ (53,092 ) Denominator: Weighted average shares used in computing basic and diluted net loss per share 69,691,841 63,270,058 69,436,365 61,813,773 Basic and diluted net loss per share $ (0.59 ) $ (0.56 ) $ (0.94 ) $ (0.86 )
Common Stock Equivalents Excluded from Computation of Diluted Net Loss Per Share	The following common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because including them would have been anti-dilutive: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (shares) (shares) (shares) (shares) Excluded securities: Convertible preferred stock issued and outstanding 177,388,428 177,388,425 177,388,428 177,388,425 Stock options issued and outstanding 60,938,265 43,719,604 53,040,604 41,694,271 Unvested stock options exercised 20,940 5,345,950 20,940 5,345,950 Restricted stock units — — — — Warrants issued and outstanding 1,199,403 962,113 1,199,403 792,449 Series E convertible preferred stock warrants 35,544,141 — 35,544,141 — Series F convertible preferred stock warrants 177,720,704 — 177,720,704 — Total common stock equivalents excluded from diluted net loss per common share computation 452,811,881 227,416,092 444,914,220 225,221,095

Convertible Preferred Stock, 36

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit (Tables)	6 Months Ended
	Jun. 30, 2017
Stockholders' Equity Note [Abstract]
Summary of Shares Authorized, Issued, Outstanding, Par Value and Liquidation Preference of Convertible Preferred Stock	The number of authorized, issued and outstanding shares, their par value and liquidation preference for each series of convertible preferred stock as of June 30, 2017 are disclosed in the table below (amounts in thousands except share and per share amounts): Convertible Preferred Stock Par Value Authorized shares Outstanding Liquidation Preference (outstanding shares) Series A $ 0.01 68,558,220 68,558,220 $ 19,774 Series A-1 0.01 24,760,915 24,760,915 49,522 Series B 0.01 35,775,880 35,775,880 21,581 Series C 0.01 24,404,770 24,404,770 70,075 Series D 0.01 23,888,640 23,888,640 165,000 Series E-1 0.01 35,544,141 — — Series E-2 0.01 16,858,078 — — Series F 0.01 177,720,707 3 — 407,511,351 177,388,428 $ 325,952
Schedule of Assumptions Used	The Company determined the fair value of the outstanding convertible Series E-1 preferred stock warrants utilizing the following assumptions as of the following dates: June 30, 2017 December 31, 2016 Volatility 40 % 40% Risk-free interest rate 2.28 % 2.45% Remaining contractual term 9.55 years 9.96 years Dividend yield — % —% The Company determined the fair value of the outstanding convertible Series F preferred stock warrants utilizing the following assumptions as of June 30, 2017 : June 30, 2017 Volatility 40 % Risk-free interest rate 2.29 % Remaining contractual term (in years) 9.66 Dividend yield — %
Schedule of Stockholders' Equity Note, Warrants or Rights	The combined activity of the Convertible Preferred Stock Warrant Liability for the six months ended June 30, 2017 is as follows (in thousands): Balance at January 1, 2017 $ 21,711 Warrants Vested 25,586 Change in Fair Value 22,817 Balance at June 30, 2017 $ 70,114

Shared Based Incentive Plan a37

Shared Based Incentive Plan and Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summarized Option Activity under Option Plan	Stock option activity under the 2005 Plan and 2015 Plan is summarized for the six months ended June 30, 2017 below: Options Issued and Outstanding Weighted- Average Exercise Price Balance as of January 1, 2017 41,395,719 $ 1.48 Options issued 30,388,611 0.22 Options exercised – vested (134,633 ) 0.11 Options forfeited (12,089,870 ) 1.17 Options expired (2,500 ) 0.22 Balance as of June 30, 2017 59,557,327 $ 0.21 Options vested and expected to vest as of June 30, 2017 47,563,036 0.21 Options vested and exercisable at June 30, 2017 21,119,436 0.18
Additional Information Regarding Common Stock Options Outstanding	Additional information regarding common stock options outstanding as of June 30, 2017 is as follows: Options Outstanding Options Vested and Exercisable Range of Exercise Prices Number Outstanding Weighted – Avg. Remaining Life Weighted –Avg. Exercise Price Number Vested Weighted – Avg. Exercise Price $ 0.02 - 0.20 8,275,145 6.56 $ 0.11 8,275,145 $ 0.11 0.20 - 0.50 51,260,062 9.09 0.22 12,822,171 0.22 0.50 - 1.13 22,120 7.35 1.13 22,120 1.13 $ 0.02 - 1.13 59,557,327 8.74 $ 0.20 21,119,436 $ 0.18
Fair Value of Stock Option Awards	The fair value of PMI’s stock option awards granted during the three months ended June 30, 2017 and 2016 was estimated at the date of grant using the Black-Scholes model with the following average assumptions: Three Months Ended Six Months Ended June 30, 2017 2016 2017 2016 Volatility of common stock N/A 50.88 % 50.28 % 50.88 % Risk-free interest rate N/A 1.29 % 2.12 % 1.29 % Expected life N/A 5.8 years 5.7 years 5.8 years Dividend yield N/A 0 % 0 % 0 %
Summarized Activities for RSU's	The following table summarizes the activities for PMI’s RSUs during the six months ended June 30, 2017 : Number of Shares Weighted-Average Grant Date Fair Value Unvested - December 31, 2016 1,995,159 $ 2.16 Granted 12,000 0.22 Vested — — Forfeited (509,479 ) 2.18 Unvested - June 30, 2017 1,497,680 $ 2.14
Stock Based Compensation Included in Consolidated Statements of Operations	The following table presents the amount of stock-based compensation related to stock-based awards granted to employees recognized in Prosper’s condensed consolidated statements of operations during the three months ended June 30, 2017 and 2016 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Origination and servicing $ 328 $ 579 $ 545 $ 1,018 Sales and marketing 141 896 311 1,632 General and administrative 2,843 4,884 5,956 8,815 Restructuring — 45 — 45 Total stock based compensation $ 3,312 $ 6,404 $ 6,812 $ 11,510

Restructuring (Tables)

Restructuring (Tables)	6 Months Ended
	Jun. 30, 2017
Restructuring and Related Activities [Abstract]
Summary of Activities Related to Prosper's Restructuring Plan	The following table summarizes the activities related to Prosper's restructuring plan (in thousands): Severance Related Facilities Related Total Balance January 1, 2017 $ 597 $ 6,052 $ 6,649 Adjustments to expense (13 ) 321 308 Sublease cash receipts — 16 16 Less: Cash paid (584 ) (3,193 ) (3,777 ) Balance June 30, 2017 $ — $ 3,196 $ 3,196

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments	Future minimum rental payments under these leases as of June 30, 2017 are as follows (in thousands): Remaining six months of 2017 2,762 2018 5,690 2019 6,026 2020 6,193 2021 6,170 2022 6,076 Thereafter 8,480 Total future operating lease obligations $ 41,397

Related Parties (Tables)

Related Parties (Tables)	6 Months Ended
	Jun. 30, 2017
Entity Information [Line Items]
Aggregate Amount of Notes Purchased and the Income Earned	The aggregate amount of the Notes and Borrower Loans purchased and the income earned by parties deemed to be affiliates and related parties of Prosper for the six months ended June 30, 2017 and 2016 , as well as the Notes and Borrower Loans outstanding as of June 30, 2017 and December 31, 2016 are summarized below (in thousands): Aggregate Amount of Notes and Borrower Loans Purchased Six Months Ended June 30, Interest Earned on Notes and Borrower Loans Six Months Ended June 30, Related Party 2017 2016 2017 2016 Executive officers and management $ 10 $ 801 $ 81 $ 110 Directors (excluding executive officers and management) 174 350 20 15 Total $ 184 $ 1,151 $ 101 $ 125 Aggregate Amount of Notes and Borrower Loans Purchased Three Months Ended June 30, Interest Earned on Notes and Borrower Loans Three Months Ended June 30, Related Party 2017 2016 2017 2016 Executive officers and management $ 5 $ 396 $ 35 $ 61 Directors (excluding executive officers and management) 85 114 10 9 Total $ 90 $ 510 $ 45 $ 70 Notes and Borrower Loans Balance as of Related Party June 30, 2017 December 31, 2016 Executive officers and management $ 1,012 $ 1,620 Directors (excluding executive officers and management) 560 537 $ 1,572 $ 2,157
Prosper Funding LLC
Entity Information [Line Items]
Aggregate Amount of Notes Purchased and the Income Earned	The aggregate amount of the Notes and Borrower Loans purchased and the income earned by parties deemed to be related parties of Prosper Funding as of June 30, 2017 and December 31, 2016 are summarized below (in thousands): Aggregate Amount of Notes and Borrower Loans Purchased Six Months Ended June 30, Interest Earned on Notes and Borrower Loans Six Months Ended June 30, Related Party 2017 2016 2017 2016 Executive officers and management $ 10 $ 801 $ 81 $ 110 Directors (excluding executive officers and management) — — — — Total $ 10 $ 801 $ 81 $ 110 Aggregate Amount of Notes and Borrower Loans Purchased Interest Earned on Notes and Borrower Loans Three Months Ended June 30, Three Months Ended June 30, Related Party 2017 2016 2017 2016 Executive officers and management $ 5 $ 396 $ 35 $ 61 Directors (excluding executive officers and management) — — — — Total $ 5 $ 396 $ 35 $ 61 Note and Borrower Loan Balance as of Related Party June 30, 2017 December 31, 2016 Executive officers and management $ 1,012 $ 1,620 Directors (excluding executive officers and management) — — $ 1,012 $ 1,620

Summary of Significant Accoun41

Summary of Significant Accounting Policies (Details) $ in Thousands	Jun. 30, 2017USD ($)
Accounting Policies [Abstract]
Non-cancelable operating lease commitments	$ 41,397

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment	$ 44,474		$ 44,474		$ 42,127
Less accumulated depreciation and amortization	(22,406)		(22,406)		(17,274)
Total property and equipment, net	22,068		22,068		24,853
Depreciation expense			6,270	$ 6,430
Property Plant And Equipment
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	2,700	$ 2,500	5,200	4,500
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment	14,370		14,370		14,107
Internal-use software and website development costs
Property, Plant and Equipment [Line Items]
Property and equipment	18,603		18,603		16,750
Capitalized internal-use software and website development costs	1,000	1,800	2,100	3,600
Office equipment and furniture
Property, Plant and Equipment [Line Items]
Property and equipment	3,010		3,010		3,010
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	7,038		7,038		7,038
Assets not yet placed in service
Property, Plant and Equipment [Line Items]
Property and equipment	1,453		1,453		1,222
Prosper Funding LLC
Property, Plant and Equipment [Line Items]
Less accumulated depreciation and amortization	(9,291)		(9,291)		(6,654)
Total property and equipment, net	9,312		9,312		10,095
Depreciation expense	1,400	$ 1,000	2,637	$ 1,864
Prosper Funding LLC | Internal-use software and website development costs
Property, Plant and Equipment [Line Items]
Property and equipment	$ 18,603		$ 18,603		$ 16,749

Borrower Loans, Loans Held fo43

Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value - Aggregate Principal Balances Outstanding and Fair Values of Borrower Loans, Notes and Loans Held for Sale (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrower Loans, at Fair Value	$ 312,272	$ 315,627
Notes, at Fair Value	(311,410)	(316,236)
Loans Held for Sale, at Fair Value	95	624
Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrower Loans, at Fair Value	312,272	315,627
Notes, at Fair Value	(311,410)	(316,236)
Loans Held for Sale, at Fair Value	95	624
Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal balance outstanding, Notes	(319,072)	(323,358)
Fair value adjustments, Notes	7,662	7,122
Notes, at Fair Value	(311,410)	(316,236)
Notes | Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal balance outstanding, Notes	(319,072)	(323,358)
Fair value adjustments, Notes	7,662	7,122
Notes, at Fair Value	(311,410)	(316,236)
Borrower Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal balance outstanding, Borrower Loans	316,378	319,143
Fair value adjustments, Borrower Loans, Loans Held for Sale	(4,106)	(3,516)
Borrower Loans, at Fair Value	312,272	315,627
Borrower Loans | Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal balance outstanding, Borrower Loans	316,378	319,143
Fair value adjustments, Borrower Loans, Loans Held for Sale	(4,106)	(3,516)
Borrower Loans, at Fair Value	312,272	315,627
Loans Held for Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value adjustments, Borrower Loans, Loans Held for Sale	(11)	(17)
Aggregate principal balance outstanding, Loans Held for Sale	106	641
Loans Held for Sale, at Fair Value	95	624
Loans Held for Sale | Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value adjustments, Borrower Loans, Loans Held for Sale	(11)	(17)
Aggregate principal balance outstanding, Loans Held for Sale	106	641
Loans Held for Sale, at Fair Value	$ 95	$ 624

Borrower Loans, Loans Held fo44

Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Loss related to credit risks on borrower loans	$ 1.2	$ 2
Minimum number of days for which loans originated were delinquent	90 days		90 days
Aggregate principal amount of loans originated	$ 2.6		$ 3.2
Fair value of loans originated	$ 0.9		1
Non accrual status past due date	120 days
Borrower loans receivable	$ 0.2		$ 0.5
Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Loss related to credit risks on borrower loans	$ 1.2
Minimum number of days for which loans originated were delinquent	90 days		90 days
Aggregate principal amount of loans originated	$ 2.6		$ 3.2
Fair value of loans originated	$ 0.9		1
Non accrual status past due date	120 days
Borrower loans receivable	$ 0.2		$ 0.5
Loans Held For Sale Borrower Loans And Underlying Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fixed interest rate, minimum	5.32%		5.32%
Fixed interest rate, maximum	33.04%		33.04%
Loans Held For Sale Borrower Loans And Underlying Notes | Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fixed interest rate, minimum	5.32%		5.32%
Fixed interest rate, maximum	33.04%		33.04%
Minimum | Loans Held For Sale Borrower Loans And Underlying Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months	36 months		36 months
Minimum | Loans Held For Sale Borrower Loans And Underlying Notes | Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months	36 months		36 months
Maximum | Loans Held For Sale Borrower Loans And Underlying Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months	60 months		60 months
Maximum | Loans Held For Sale Borrower Loans And Underlying Notes | Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months	60 months		60 months

Loan Servicing Assets and Lia45

Loan Servicing Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Servicing Assets And Liabilities Fair Value [Line Items]
Gain (loss) on sale of borrower loans	$ (3,803)	$ 687	$ (3,485)	$ (3,104)
Fair Value of Warrants Vested on Sale of Borrower Loans	16,887	0	20,194	0
Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Gain (loss) on sale of borrower loans	13,084	687	16,709	(3,104)
Borrower Loans
Servicing Assets And Liabilities Fair Value [Line Items]
Outstanding principle	3,600,000		$ 3,600,000		$ 3,500,000
Fixed interest rate, minimum			5.32%		5.32%
Fixed interest rate, maximum			35.52%		35.52%
Contractually specified servicing fees, late charges and ancillary fees	9,400	10,400	$ 18,200	20,000
Borrower Loans | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Outstanding principle	3,500,000		$ 3,500,000		$ 3,400,000
Fixed interest rate, minimum			5.32%		5.32%
Fixed interest rate, maximum			35.52%		35.52%
Contractually specified servicing fees, late charges and ancillary fees	$ 9,200	$ 10,300	$ 17,900	$ 19,700
Minimum | Borrower Loans
Servicing Assets And Liabilities Fair Value [Line Items]
Maturity, in months			36 months		36 months
Minimum | Borrower Loans | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Maturity, in months			36 months		36 months
Maximum | Borrower Loans
Servicing Assets And Liabilities Fair Value [Line Items]
Maturity, in months			60 months		60 months
Maximum | Borrower Loans | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Maturity, in months			60 months		60 months

Available for Sale Investment46

Available for Sale Investments, at Fair Value - Schedule of Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Available for Sale Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 8,001	$ 32,777
Gross Unrealized Gains	0	5
Gross Unrealized Losses	(4)	(13)
Fair Value	7,997	32,769
Fixed Maturity Securities | US Treasury securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	5,501	8,516
Gross Unrealized Gains	0	3
Gross Unrealized Losses	(3)	(3)
Fair Value	5,498	8,516
Fixed Maturity Securities | Agency bonds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	2,500	2,499
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(1)	0
Fair Value	$ 2,499	2,500
Fixed Maturity Securities | Corporate debt securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		21,762
Gross Unrealized Gains		1
Gross Unrealized Losses		(10)
Fair Value		$ 21,753

Available for Sale Investment47

Available for Sale Investments, at Fair Value - Summary of Available for Sale Investments of Continuous Unrealized Loss (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Fair value, less than 12 months	$ 5,498	$ 0
Unrealized losses, less than 12 months	(3)	0
Fair value, 12 months or longer	2,499	19,150
Unrealized losses, 12 months or longer	(1)	(13)
Fair Value	7,997	19,150
Unrealized Losses	(4)	(13)
Fixed Maturity Securities | US Treasury securities
Schedule Of Available For Sale Securities [Line Items]
Fair value, less than 12 months	5,498	0
Unrealized losses, less than 12 months	(3)	0
Fair value, 12 months or longer		4,499
Unrealized losses, 12 months or longer		(3)
Fair Value	5,498	4,499
Unrealized Losses	(3)	(3)
Fixed Maturity Securities | Agency bonds
Schedule Of Available For Sale Securities [Line Items]
Fair value, less than 12 months	0
Unrealized losses, less than 12 months	0
Fair value, 12 months or longer	2,499
Unrealized losses, 12 months or longer	(1)
Fair Value	2,499
Unrealized Losses	$ (1)
Fixed Maturity Securities | Corporate debt securities
Schedule Of Available For Sale Securities [Line Items]
Fair value, less than 12 months		0
Unrealized losses, less than 12 months		0
Fair value, 12 months or longer		14,651
Unrealized losses, 12 months or longer		(10)
Fair Value		14,651
Unrealized Losses		$ (10)

Available for Sale Investment48

Available for Sale Investments, at Fair Value - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Impairment charges recognized during period	$ 0
Proceeds from investments	16,163,000	$ 9,193,000
Available-for-sale investments, realized gains	$ 12,000

Available for Sale Investment49

Available for Sale Investments, at Fair Value - Schedule of Maturities of Available for Sale Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Within 1 year	$ 7,997	$ 32,769
After 1 year through 5 years	0	0
After 5 years to 10 years	0	0
After 10 years	0	0
Fair value	7,997	32,769
Amortized cost within 1 year	8,001	32,777
Amortized cost after 1 year through 5 years	0	0
Amortized cost after 5 years to 10 years	0	0
Amortized cost after 10 years	0	0
Amortized cost	8,001	32,777
Corporate debt securities
Schedule Of Available For Sale Securities [Line Items]
Within 1 year		21,753
After 1 year through 5 years		0
After 5 years to 10 years		0
After 10 years		0
Fair value		21,753
US Treasury securities
Schedule Of Available For Sale Securities [Line Items]
Within 1 year	5,498	8,516
After 1 year through 5 years		0
After 5 years to 10 years		0
After 10 years		0
Fair value	5,498	8,516
Agency bonds
Schedule Of Available For Sale Securities [Line Items]
Within 1 year	2,499	2,500
After 1 year through 5 years		0
After 5 years to 10 years		0
After 10 years		0
Fair value	$ 2,499	$ 2,500

Fair Value of Assets and Liab50

Fair Value of Assets and Liabilities - Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets:
Borrower Loans	$ 312,272	$ 315,627
Loans Held for Sale	95	624
Available for Sale Investments, at Fair Value	7,997	32,769
Servicing Assets	13,489	12,786
Total Assets	333,853	361,806
Liabilities:
Notes	311,410	316,236
Servicing Liabilities	111	198
Convertible Preferred Stock Warrant Liability	70,114	21,711
Loan Trailing Fee Liability	1,655	665
Total Liabilities	383,290	338,810
Prosper Funding LLC
Assets:
Borrower Loans	312,272	315,627
Loans Held for Sale	95	624
Servicing Assets	13,297	12,461
Total Assets	325,664	328,712
Liabilities:
Notes	311,410	316,236
Servicing Liabilities	111	198
Loan Trailing Fee Liability	1,655	665
Total Liabilities	313,176	317,099
Level 1 Inputs
Assets:
Borrower Loans	0	0
Loans Held for Sale	0	0
Available for Sale Investments, at Fair Value	0	0
Servicing Assets	0	0
Total Assets	0	0
Liabilities:
Notes	0	0
Servicing Liabilities	0	0
Convertible Preferred Stock Warrant Liability	0	0
Loan Trailing Fee Liability	0	0
Total Liabilities	0	0
Level 1 Inputs | Prosper Funding LLC
Assets:
Borrower Loans	0	0
Loans Held for Sale	0	0
Servicing Assets	0	0
Total Assets	0	0
Liabilities:
Notes	0	0
Servicing Liabilities	0	0
Loan Trailing Fee Liability		0
Total Liabilities	0	0
Level 2 Inputs
Assets:
Borrower Loans	0	0
Loans Held for Sale	0	0
Available for Sale Investments, at Fair Value	7,997	32,769
Servicing Assets	0	0
Total Assets	7,997	32,769
Liabilities:
Notes	0	0
Servicing Liabilities	0	0
Convertible Preferred Stock Warrant Liability	0	0
Loan Trailing Fee Liability	0	0
Total Liabilities	0	0
Level 2 Inputs | Prosper Funding LLC
Assets:
Borrower Loans	0	0
Loans Held for Sale	0	0
Servicing Assets	0	0
Total Assets	0	0
Liabilities:
Notes	0	0
Servicing Liabilities	0	0
Loan Trailing Fee Liability		0
Total Liabilities	0	0
Level 3 Inputs
Assets:
Borrower Loans	312,272	315,627
Loans Held for Sale	95	624
Available for Sale Investments, at Fair Value	0	0
Servicing Assets	13,489	12,786
Total Assets	325,856	329,037
Liabilities:
Notes	311,410	316,236
Servicing Liabilities	111	198
Convertible Preferred Stock Warrant Liability	70,114	21,711
Loan Trailing Fee Liability	1,655	665
Total Liabilities	383,290	338,810
Level 3 Inputs | Prosper Funding LLC
Assets:
Borrower Loans	312,272	315,627
Loans Held for Sale	95	624
Servicing Assets	13,297	12,461
Total Assets	325,664	328,712
Liabilities:
Notes	311,410	316,236
Servicing Liabilities	111	198
Loan Trailing Fee Liability	1,655	665
Total Liabilities	$ 313,176	$ 317,099

Fair Value of Assets and Liab51

Fair Value of Assets and Liabilities - Borrower Loans, Loans Held For Sale and Notes - Quantitative Information about the Significant Unobservable Inputs (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	4.30%	4.00%
Default rate	1.90%	1.70%
Minimum | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	4.30%	4.00%
Default rate	1.90%	1.70%
Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	15.20%	15.90%
Default rate	15.20%	14.90%
Maximum | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	15.20%	15.90%
Default rate	15.20%	14.90%

Fair Value of Assets and Liab52

Fair Value of Assets and Liabilities - Servicing Rights - Quantitative Information about the Significant Unobservable Inputs (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Servicing Liabilities at Fair Value [Line Items]
Market servicing rate	0.625%	0.625%
Prosper Funding LLC
Servicing Liabilities at Fair Value [Line Items]
Market servicing rate	0.625%	0.625%
Minimum
Servicing Liabilities at Fair Value [Line Items]
Discount rate	15.00%	15.00%
Default rate	1.60%	1.50%
Prepayment rate	14.40%	13.60%
Minimum | Prosper Funding LLC
Servicing Liabilities at Fair Value [Line Items]
Discount rate	15.00%	15.00%
Default rate	1.60%	1.50%
Prepayment rate	14.40%	13.60%
Maximum
Servicing Liabilities at Fair Value [Line Items]
Discount rate	25.00%	25.00%
Default rate	15.70%	15.20%
Prepayment rate	26.70%	26.60%
Maximum | Prosper Funding LLC
Servicing Liabilities at Fair Value [Line Items]
Discount rate	25.00%	25.00%
Default rate	15.70%	15.20%
Prepayment rate	26.70%	26.60%

Fair Value of Assets and Liab53

Fair Value of Assets and Liabilities - Summary of Level 3 Borrower Loans, Loans Held for Sale and Notes, Measured at Fair Value on a Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Asset And Liability [Roll Forward]
Beginning balance, Total	$ 701	$ 916	$ 15	$ (100)
Purchase of Borrower Loans/Issuance of Notes	722,397	426,762	1,246,260	1,358,079
Principal repayments	633	(464)	2,740	607
Borrower Loans sold to third parties	(722,698)	(421,810)	(1,248,306)	(1,353,259)
Other changes	(146)	(193)	272	(39)
Change in fair value	70	(2)	(24)	(79)
Ending balance, Total	957	5,209	957	5,209
Prosper Funding LLC
Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Asset And Liability [Roll Forward]
Beginning balance, Total	701	916	15	(100)
Originations	722,397	426,762	1,246,260	1,358,079
Principal repayments	633	(464)	2,740	607
Borrower Loans sold to third parties	(722,698)	(421,810)	(1,248,306)	(1,353,259)
Other changes	(146)	(193)	272	(39)
Change in fair value	70	(2)	(24)	(79)
Ending balance, Total	957	5,209	957	5,209
Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance, Liabilities	(316,944)	(302,357)	(316,236)	(297,405)
Purchase of Borrower Loans/Issuance of Notes	(49,692)	(53,873)	(106,506)	(109,147)
Principal repayments	48,695	41,057	100,274	83,119
Borrower Loans sold to third parties	0	499	0	1,081
Other changes	(156)	(191)	266	(33)
Change in fair value	6,687	5,335	10,792	12,855
Ending balance, Liabilities	(311,410)	(309,530)	(311,410)	(309,530)
Notes | Prosper Funding LLC
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance, Liabilities	(316,944)	(302,357)	(316,236)	(297,405)
Originations	(49,692)	(53,873)	(106,506)	(109,147)
Principal repayments	48,695	41,057	100,274	83,119
Borrower Loans sold to third parties	0	499	0	1,081
Other changes	(156)	(191)	266	(33)
Change in fair value	6,687	5,335	10,792	12,855
Ending balance, Liabilities	(311,410)	(309,530)	(311,410)	(309,530)
Borrower Loans
Changes in Level 3 assets measured at fair value on a recurring basis [Abstract]
Beginning balance, Assets	317,536	303,243	315,627	297,273
Purchase of Borrower Loans/Issuance of Notes	50,260	54,044	106,940	109,215
Principal repayments	(48,048)	(41,390)	(97,492)	(82,376)
Borrower Loans sold to third parties	(869)	(525)	(1,990)	(1,138)
Other changes	10	(2)	9	(6)
Change in fair value	(6,617)	(5,336)	(10,822)	(12,934)
Ending balance, Assets	312,272	310,034	312,272	310,034
Borrower Loans | Prosper Funding LLC
Changes in Level 3 assets measured at fair value on a recurring basis [Abstract]
Beginning balance, Assets	317,536	303,243	315,627	297,273
Originations	50,260	54,044	106,940	109,215
Principal repayments	(48,048)	(41,390)	(97,492)	(82,376)
Borrower Loans sold to third parties	(869)	(525)	(1,990)	(1,138)
Other changes	10	(2)	9	(6)
Change in fair value	(6,617)	(5,336)	(10,822)	(12,934)
Ending balance, Assets	312,272	310,034	312,272	310,034
Loans Held for Sale
Changes in Level 3 assets measured at fair value on a recurring basis [Abstract]
Beginning balance, Assets	109	30	624	32
Purchase of Borrower Loans/Issuance of Notes	721,829	426,591	1,245,826	1,358,011
Principal repayments	(14)	(131)	(42)	(136)
Borrower Loans sold to third parties	(721,829)	(421,784)	(1,246,316)	(1,353,202)
Other changes	0	0	(3)	0
Change in fair value	0	(1)	6	0
Ending balance, Assets	95	4,705	95	4,705
Loans Held for Sale | Prosper Funding LLC
Changes in Level 3 assets measured at fair value on a recurring basis [Abstract]
Beginning balance, Assets	109	30	624	32
Originations	721,829	426,591	1,245,826	1,358,011
Principal repayments	(14)	(131)	(42)	(136)
Borrower Loans sold to third parties	(721,829)	(421,784)	(1,246,316)	(1,353,202)
Other changes	0	0	(3)	0
Change in fair value	0	(1)	6	0
Ending balance, Assets	$ 95	$ 4,705	$ 95	$ 4,705

Fair Value of Assets and Liab54

Fair Value of Assets and Liabilities - Schedule of Servicing Assets and Liabilities and Loan Trailing (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Servicing Asset at Fair Value, Beginning Balance		$ 12,786		$ 12,786
Servicing Asset at Fair Value, Ending Balance	$ 13,489			13,489
Servicing Liability at Amortized Cost [Roll Forward]
Servicing Liability at Fair Value, Beginning Balance		198		198
Servicing Liability at Fair Value, Ending Balance	111			111
Prosper Funding LLC
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Servicing Asset at Fair Value, Beginning Balance		12,461		12,461
Servicing Asset at Fair Value, Ending Balance	13,297			13,297
Servicing Liability at Amortized Cost [Roll Forward]
Servicing Liability at Fair Value, Beginning Balance		198		198
Servicing Liability at Fair Value, Ending Balance	111			111
Servicing Assets
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Servicing Asset at Fair Value, Beginning Balance	12,436	12,786	$ 15,548	12,786	$ 14,363
Additions		3,768	1,729	6,532	5,750
Less: Changes in fair value		(2,715)	(2,980)	(5,829)	(5,816)
Servicing Asset at Fair Value, Ending Balance	13,489	12,436	14,297	13,489	14,297
Servicing Assets | Prosper Funding LLC
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Servicing Asset at Fair Value, Beginning Balance	12,190	12,461	14,929	12,461	13,605
Additions	3,768		1,729	6,532	5,750
Less: Changes in fair value	(2,661)		(2,860)	(5,696)	(5,557)
Servicing Asset at Fair Value, Ending Balance	13,297	12,190	13,798	13,297	13,798
Servicing Liabilities
Servicing Liability at Amortized Cost [Roll Forward]
Servicing Liability at Fair Value, Beginning Balance	147	198	398	198	484
Additions		0	0	0	9
Less: Changes in fair value		(36)	(74)	(87)	(169)
Servicing Liability at Fair Value, Ending Balance	111	147	324	111	324
Servicing Liabilities | Prosper Funding LLC
Servicing Liability at Amortized Cost [Roll Forward]
Servicing Liability at Fair Value, Beginning Balance	147	198	398	198	484
Additions	0		0	0	9
Less: Changes in fair value	(36)		(74)	(87)	(169)
Servicing Liability at Fair Value, Ending Balance	111	147	$ 324	111	$ 324
Trailing Fee
Servicing Liability at Amortized Cost [Roll Forward]
Beginning balance		665		665
Issuances				1,216
Cash payment of Loan Trailing Fee				(351)
Change in fair value				125
Ending balance	1,655			1,655
Trailing Fee | Prosper Funding LLC
Servicing Liability at Amortized Cost [Roll Forward]
Beginning balance		$ 665		665
Issuances				1,216
Cash payment of Loan Trailing Fee				(351)
Change in fair value				125
Ending balance	$ 1,655			$ 1,655

Fair Value of Assets and Liab55

Fair Value of Assets and Liabilities - Fair Value Assumptions for Borrower Loans, Loans Held for Sale and Notes (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Discount rate assumption | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	7.55%
Discount rate assumption | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	7.55%
Discount rate assumption | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	7.55%
Discount rate assumption | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	7.55%
Discount rate assumption | 100 basis point increase | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	$ 308,250
Discount rate assumption | 100 basis point increase | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	308,250
Discount rate assumption | 100 basis point increase | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	309,203
Discount rate assumption | 100 basis point increase | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	309,203
Discount rate assumption | 200 basis point increase | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	305,170
Discount rate assumption | 200 basis point increase | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	305,170
Discount rate assumption | 200 basis point increase | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	306,119
Discount rate assumption | 200 basis point increase | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	306,119
Discount rate assumption | 100 basis point decrease | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	314,653
Discount rate assumption | 100 basis point decrease | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	314,653
Discount rate assumption | 100 basis point decrease | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	315,614
Discount rate assumption | 100 basis point decrease | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	315,614
Discount rate assumption | 200 basis point decrease | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	317,984
Discount rate assumption | 200 basis point decrease | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	317,984
Discount rate assumption | 200 basis point decrease | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	318,948
Discount rate assumption | 200 basis point decrease | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	$ 318,948
Default rate assumption | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate	12.96%
Default rate assumption | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate	12.96%
Default rate assumption | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate	12.96%
Default rate assumption | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Default rate	12.96%
Default rate assumption | 100 basis point increase | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	$ 307,645
Default rate assumption | 100 basis point increase | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	307,645
Default rate assumption | 100 basis point increase | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	308,608
Default rate assumption | 100 basis point increase | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	308,608
Default rate assumption | 200 basis point increase | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	304,015
Default rate assumption | 200 basis point increase | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	304,015
Default rate assumption | 200 basis point increase | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	304,984
Default rate assumption | 200 basis point increase | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	304,984
Default rate assumption | 100 basis point decrease | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	315,200
Default rate assumption | 100 basis point decrease | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	315,200
Default rate assumption | 100 basis point decrease | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	316,150
Default rate assumption | 100 basis point decrease | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	316,150
Default rate assumption | 200 basis point decrease | Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	319,038
Default rate assumption | 200 basis point decrease | Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes	319,038
Default rate assumption | 200 basis point decrease | Borrower Loans and Loans Held for Sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	319,980
Default rate assumption | 200 basis point decrease | Borrower Loans and Loans Held for Sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans	$ 319,980

Fair Value of Assets and Liab56

Fair Value of Assets and Liabilities - Schedule of Prosper's and Prosper Funding's Estimated Fair Value of Servicing Assets and Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Servicing Assets And Liabilities Fair Value [Line Items]
Market servicing rate assumptions	0.625%	0.625%
Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Market servicing rate assumptions	0.625%	0.625%
Servicing Assets
Servicing Assets And Liabilities Fair Value [Line Items]
Market servicing rate assumptions	0.625%
Resulting fair value from:
Servicing Asset, Market servicing rate increase to 0.65%	$ 12,613
Servicing Asset, Market servicing rate decrease to 0.60%	$ 14,365
Weighted average prepayment assumptions	20.09%
Resulting fair value from:
Weighted average default assumptions	12.18%
Servicing Assets | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Market servicing rate assumptions	0.625%
Resulting fair value from:
Servicing Asset, Market servicing rate increase to 0.65%	$ 12,434
Servicing Asset, Market servicing rate decrease to 0.60%	$ 14,160
Weighted average prepayment assumptions	20.09%
Resulting fair value from:
Weighted average default assumptions	12.18%
Servicing Liabilities
Servicing Assets And Liabilities Fair Value [Line Items]
Market servicing rate assumptions	0.625%
Resulting fair value from:
Servicing Liabilities, Market servicing rate increase to 0.65%	$ 122
Servicing Liabilities, Market servicing rate decrease to 0.60%	$ 100
Weighted average prepayment assumptions	20.09%
Resulting fair value from:
Weighted average default assumptions	12.18%
Servicing Liabilities | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Market servicing rate assumptions	0.625%
Resulting fair value from:
Servicing Asset, Market servicing rate increase to 0.65%	$ 122
Servicing Asset, Market servicing rate decrease to 0.60%	$ 100
Weighted average prepayment assumptions	20.09%
Resulting fair value from:
Weighted average default assumptions	12.18%
Prepayment rate assumption | Servicing Assets | Applying a 1.1 multiplier to prepayment rate
Resulting fair value from:
Servicing Asset, Applying a 1.1 multiplier to prepayment rate	$ 13,301
Prepayment rate assumption | Servicing Assets | Applying a 1.1 multiplier to prepayment rate | Prosper Funding LLC
Resulting fair value from:
Servicing Asset, Applying a 1.1 multiplier to prepayment rate	13,112
Prepayment rate assumption | Servicing Assets | Applying a 0.9 multiplier to prepayment rate
Resulting fair value from:
Servicing Asset, Applying a 0.9 multiplier to prepayment rate	13,678
Prepayment rate assumption | Servicing Assets | Applying a 0.9 multiplier to prepayment rate | Prosper Funding LLC
Resulting fair value from:
Servicing Asset, Applying a 0.9 multiplier to prepayment rate	13,484
Prepayment rate assumption | Servicing Liabilities | Applying a 1.1 multiplier to prepayment rate
Resulting fair value from:
Servicing Liabilities, Applying a 1.1 multiplier to prepayment rate	109
Prepayment rate assumption | Servicing Liabilities | Applying a 1.1 multiplier to prepayment rate | Prosper Funding LLC
Resulting fair value from:
Servicing Asset, Applying a 1.1 multiplier to prepayment rate	109
Prepayment rate assumption | Servicing Liabilities | Applying a 0.9 multiplier to prepayment rate
Resulting fair value from:
Servicing Liabilities, Applying a 0.9 multiplier to prepayment rate	113
Prepayment rate assumption | Servicing Liabilities | Applying a 0.9 multiplier to prepayment rate | Prosper Funding LLC
Resulting fair value from:
Servicing Asset, Applying a 0.9 multiplier to prepayment rate	113
Default rate assumption | Servicing Assets | Applying a 1.1 multiplier to default rate
Applying Multiplier, Default Rate [Abstract]
Servicing Asset, Applying a 1.1 multiplier to default rate	13,301
Default rate assumption | Servicing Assets | Applying a 1.1 multiplier to default rate | Prosper Funding LLC
Applying Multiplier, Default Rate [Abstract]
Servicing Asset, Applying a 1.1 multiplier to default rate	13,112
Default rate assumption | Servicing Assets | Applying a 0.9 multiplier to default rate
Applying Multiplier, Default Rate [Abstract]
Servicing Asset, Applying a 0.9 multiplier to default rate	13,680
Default rate assumption | Servicing Assets | Applying a 0.9 multiplier to default rate | Prosper Funding LLC
Applying Multiplier, Default Rate [Abstract]
Servicing Asset, Applying a 0.9 multiplier to default rate	13,486
Default rate assumption | Servicing Liabilities | Applying a 1.1 multiplier to default rate
Applying Multiplier, Default Rate [Abstract]
Servicing Liabilities, Applying a 1.1 multiplier to default rate	111
Default rate assumption | Servicing Liabilities | Applying a 1.1 multiplier to default rate | Prosper Funding LLC
Applying Multiplier, Default Rate [Abstract]
Servicing Asset, Applying a 1.1 multiplier to default rate	111
Default rate assumption | Servicing Liabilities | Applying a 0.9 multiplier to default rate
Applying Multiplier, Default Rate [Abstract]
Servicing Liabilities, Applying a 0.9 multiplier to default rate	111
Default rate assumption | Servicing Liabilities | Applying a 0.9 multiplier to default rate | Prosper Funding LLC
Applying Multiplier, Default Rate [Abstract]
Servicing Asset, Applying a 0.9 multiplier to default rate	$ 111

Fair Value of Assets and Liab57

Fair Value of Assets and Liabilities - Schedule of Prosper's and Prosper Funding's Estimated Fair Value of Servicing Assets and Liabilities Additional Info (Details)	6 Months Ended
	Jun. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing rate increase	0.65%
Servicing rate decrease	0.60%
Prepayment rate assumption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepayment rate increase	1.10%
Prepayment rate decrease	0.90%
Default rate assumption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Default rate increase	1.10%
Default rate decrease	0.90%
Prosper Funding LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing rate increase	0.65%
Servicing rate decrease	0.60%
Prosper Funding LLC | Prepayment rate assumption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepayment rate increase	1.10%
Prepayment rate decrease	0.90%
Prosper Funding LLC | Default rate assumption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Default rate increase	1.10%
Default rate decrease	0.90%

Goodwill And Other Intangible58

Goodwill And Other Intangible Assets - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Goodwill And Other Intangible Assets [Line Items]
Goodwill	$ 36,368,000		$ 36,368,000		$ 36,368,000
Goodwill impairment expense			0
Intangible assets, net	1,862,000		1,862,000		$ 9,212,000
Impairment loss			6,319,000	$ 0
Amortization of intangible assets	200,000	$ 1,000,000	1,000,000	$ 2,000,000
User base and customer relationships
Goodwill And Other Intangible Assets [Line Items]
Intangible assets, net	347,000		$ 347,000
Intangible assets amortized period			7 years 9 months 18 days
User base and customer relationships | Minimum
Goodwill And Other Intangible Assets [Line Items]
Intangible assets amortized period			3 years
User base and customer relationships | Maximum
Goodwill And Other Intangible Assets [Line Items]
Intangible assets amortized period			10 years
Developed technology
Goodwill And Other Intangible Assets [Line Items]
Intangible assets, net	1,515,000		$ 1,515,000
Intangible assets amortized period			9 months 18 days
Developed technology | Minimum
Goodwill And Other Intangible Assets [Line Items]
Intangible assets amortized period			3 years
Developed technology | Maximum
Goodwill And Other Intangible Assets [Line Items]
Intangible assets amortized period			5 years
Brand name
Goodwill And Other Intangible Assets [Line Items]
Intangible assets, net	$ 0		$ 0
Intangible assets amortized period			1 year

Goodwill And Other Intangible59

Goodwill And Other Intangible Assets - Summary of Other Intangible for the Period Presented (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 8,975
Accumulated Amortization	(7,113)
Net Carrying Value	1,862	$ 9,212
User base and customer relationships
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	4,122
Accumulated Amortization	(3,775)
Net Carrying Value	$ 347
Remaining Useful Life (In Years)	7 years 9 months 18 days
Developed technology
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 4,793
Accumulated Amortization	(3,278)
Net Carrying Value	$ 1,515
Remaining Useful Life (In Years)	9 months 18 days
Brand name
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 60
Accumulated Amortization	(60)
Net Carrying Value	$ 0
Remaining Useful Life (In Years)	1 year

Goodwill And Other Intangible60

Goodwill And Other Intangible Assets - Summary of Estimated Amortization of Purchased Intangible Assets (Details) $ in Thousands	Jun. 30, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2017	$ 355
2,018	379
2,019	279
2,020	219
2,021	500
Net Carrying Value	$ 1,732

Assets Held for Sale (Details)

Assets Held for Sale (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment loss		$ 6,319	$ 0
Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment loss	$ 2,000	6,300
Intangible Assets	130	130
Goodwill	12	12
Total Assets Held for Sale	$ 142	$ 142

Other Liabilities (Details)

Other Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Other Liabilities [Abstract]
Class action settlement liability	$ 0	$ 2,996
Repurchase liability for unvested restricted stock awards	24	118
Loan trailing fee	1,655	665
Servicing liabilities	111	198
Deferred rent	4,133	4,469
Restructuring liability	3,414	6,052
Other	3,438	2,675
Total Other Liabilities	$ 12,775	$ 17,173

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator:
Net loss available to common stockholders for basic and diluted EPS	$ (41,405)	$ (35,628)	$ (65,426)	$ (53,092)
Denominator:
Weighted average shares used in computing basic and diluted net loss per share (in shares)	69,691,841	63,270,058	69,436,365	61,813,773
Basic and diluted net loss per share (in dollars per share)	$ (0.59)	$ (0.56)	$ (0.94)	$ (0.86)

Net Loss Per Share - Common Sto

Net Loss Per Share - Common Stock Equivalents Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net loss per common share computation (in shares)	452,811,881	227,416,092	444,914,220	225,221,095
Convertible preferred stock issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net loss per common share computation (in shares)	177,388,428	177,388,425	177,388,428	177,388,425
Stock options issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net loss per common share computation (in shares)	60,938,265	43,719,604	53,040,604	41,694,271
Unvested stock options exercised
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net loss per common share computation (in shares)	20,940	5,345,950	20,940	5,345,950
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net loss per common share computation (in shares)	0	0	0	0
Warrants issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net loss per common share computation (in shares)	1,199,403	962,113	1,199,403	792,449
Series E convertible preferred stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net loss per common share computation (in shares)	35,544,141	0	35,544,141	0
Series F convertible preferred stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net loss per common share computation (in shares)	177,720,704	0	177,720,704	0

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Details)	Feb. 16, 2016
Earnings Per Share [Abstract]
Stock split conversion ratio	5

Convertible Preferred Stock, 66

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit - Additional Information (Details)	Dec. 16, 2016$ / sharesshares	Feb. 16, 2016	Jun. 30, 2017USD ($)$ / sharesshares	Jun. 30, 2017USD ($)time$ / sharesshares	Dec. 31, 2016vote / shares$ / sharesshares	Feb. 27, 2017$ / sharesshares	May 31, 2016$ / sharesshares
Class of Stock [Line Items]
Stock split conversion ratio		5
Common and preferred stock, shares authorized (in shares)							957,511,351
Common stock, shares authorized (in shares)			550,000,000	550,000,000	338,222,103		550,000,000
Common stock, par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01	$ 0.01		$ 0.01
Preferred stock, shares authorized (in shares)			407,511,351	407,511,351	217,388,425		407,511,351
Preferred stock, par value (in dollars per share) | $ / shares							$ 0.01
Common stock, shares issued (in shares)			70,719,747	70,719,747	70,843,044
Common stock, shares outstanding (in shares)			69,783,812	69,783,812	69,907,109
Common stock, vote per share | vote / shares					1
Common Stock
Class of Stock [Line Items]
Stock split conversion ratio		5
Exercise of stock options (in shares)				134,633
Cash proceeds | $				$ 14,000
Unvested restricted stock outstanding (in shares)			20,940	20,940	1,126,210
Stock repurchase upon termination of employment (in shares)				266,130
Aggregate price for repurchase of common stock | $				$ 64,000
Series E-1
Class of Stock [Line Items]
Warrant to purchase (number of shares)	20,267,135
Exercise price (in dollars per share) | $ / shares	$ 0.01
Liquidation preference (in dollars per share) | $ / shares			$ 0.84	$ 0.84
Preferred stock, shares authorized (in shares)			35,544,141	35,544,141
Series E-2
Class of Stock [Line Items]
Warrant to purchase (number of shares)						15,277,006
Exercise price (in dollars per share) | $ / shares						$ 0.01
Liquidation preference (in dollars per share) | $ / shares			$ 0.84	$ 0.84
Warrant expiration period	10 years
Expense amount | $				$ 14,900,000
Preferred stock, shares authorized (in shares)			16,858,078	16,858,078
Series F convertible preferred stock warrants
Class of Stock [Line Items]
Warrant to purchase (number of shares)			177,720,706	177,720,706		177,720,706
Exercise price (in dollars per share) | $ / shares			$ 0.01	$ 0.01		$ 0.01
Liquidation preference (in dollars per share) | $ / shares			$ 0.84	$ 0.84
Expense amount | $			$ 7,500,000
Preferred stock, shares authorized (in shares)			177,720,707	177,720,707
Series B
Class of Stock [Line Items]
IPO value (at least) | $				$ 2,000,000,000
Aggregate proceeds (at least) | $				$ 100,000,000
Voting power (at least)				60.00%
Liquidation preference (in dollars per share) | $ / shares			$ 0.60	$ 0.60
Preferred stock, shares authorized (in shares)			35,775,880	35,775,880
Series A One Convertible Preferred Stock
Class of Stock [Line Items]
Voting power (at least)				14.00%
Conversion ratio			1,000,000	1,000,000
Liquidation preference (in dollars per share) | $ / shares			$ 2	$ 2
Series A
Class of Stock [Line Items]
Conversion ratio			1	1
Times the original issue | time				3
Liquidation preference (in dollars per share) | $ / shares			$ 0.29	$ 0.29
Preferred stock, shares authorized (in shares)			68,558,220	68,558,220
Series C
Class of Stock [Line Items]
Liquidation preference (in dollars per share) | $ / shares			$ 2.87	$ 2.87
Preferred stock, shares authorized (in shares)			24,404,770	24,404,770
Series D Convertible Preferred Stock
Class of Stock [Line Items]
Liquidation preference (in dollars per share) | $ / shares			$ 6.91	$ 6.91

Convertible Preferred Stock, 67

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit - Summary of Shares Authorized, Issued, Outstanding, Par Value and Liquidation Preference of Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	May 31, 2016
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Convertible preferred stock, shares authorized (in shares)	407,511,351	217,388,425	407,511,351
Convertible preferred stock, shares outstanding (in shares)	177,388,428	177,388,425
Convertible preferred stock, shares issued (in shares)	177,388,428	177,388,425
Convertible preferred stock, aggregate liquidation preference	$ 325,952	$ 325,952
Series A
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, shares authorized (in shares)	68,558,220
Convertible preferred stock, shares outstanding (in shares)	68,558,220
Convertible preferred stock, shares issued (in shares)	68,558,220
Convertible preferred stock, aggregate liquidation preference	$ 19,774
Series A-1
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, shares authorized (in shares)	24,760,915
Convertible preferred stock, shares outstanding (in shares)	24,760,915
Convertible preferred stock, shares issued (in shares)	24,760,915
Convertible preferred stock, aggregate liquidation preference	$ 49,522
Series B
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, shares authorized (in shares)	35,775,880
Convertible preferred stock, shares outstanding (in shares)	35,775,880
Convertible preferred stock, shares issued (in shares)	35,775,880
Convertible preferred stock, aggregate liquidation preference	$ 21,581
Series C
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, shares authorized (in shares)	24,404,770
Convertible preferred stock, shares outstanding (in shares)	24,404,770
Convertible preferred stock, shares issued (in shares)	24,404,770
Convertible preferred stock, aggregate liquidation preference	$ 70,075
Series D
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, shares authorized (in shares)	23,888,640
Convertible preferred stock, shares outstanding (in shares)	23,888,640
Convertible preferred stock, shares issued (in shares)	23,888,640
Convertible preferred stock, aggregate liquidation preference	$ 165,000
Series E-1
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, shares authorized (in shares)	35,544,141
Convertible preferred stock, shares outstanding (in shares)	0
Convertible preferred stock, shares issued (in shares)	0
Convertible preferred stock, aggregate liquidation preference	$ 0
Series E-2
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, shares authorized (in shares)	16,858,078
Convertible preferred stock, shares outstanding (in shares)	0
Convertible preferred stock, shares issued (in shares)	0
Convertible preferred stock, aggregate liquidation preference	$ 0
Series F convertible preferred stock warrants
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, shares authorized (in shares)	177,720,707
Convertible preferred stock, shares outstanding (in shares)	3
Convertible preferred stock, shares issued (in shares)	3
Convertible preferred stock, aggregate liquidation preference	$ 0

Convertible Preferred Stock, 68

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit - Schedule of Assumptions Used (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Series E-1
Class of Stock [Line Items]
Volatility	40.00%	40.00%
Risk-free interest rate	2.28%	2.45%
Remaining contractual term	9 years 6 months 18 days	9 years 11 months 16 days
Dividend yield	0.00%	0.00%
Series F convertible preferred stock warrants
Class of Stock [Line Items]
Volatility	40.00%
Risk-free interest rate	2.29%
Remaining contractual term	9 years 7 months 28 days
Dividend yield	0.00%

Convertible Preferred Stock, 69

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit - Warrant Liability (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Warrants or Rights [Roll Forward]
Change in Fair Value	$ 22,817	$ 0
Convertible Preferred Stock Warrant
Warrants or Rights [Roll Forward]
Balance at January 1, 2017	21,711
Warrants Vested	25,586
Change in Fair Value	22,817
Balance at June 30, 2017	$ 70,114

Shared Based Incentive Plan a70

Shared Based Incentive Plan and Compensation - Additional Information (Details)	Feb. 16, 2016	Jun. 30, 2017USD ($)shares	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)shares	Jun. 30, 2016USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options exercisable, maximum period				10 years
Stock split conversion ratio	5
Financial statement impact amount				$ 6,812,000	$ 11,510,000
Unamortized expense related to unvested stock-based awards		$ 21,200,000		$ 21,200,000
Dividend yield			0.00%	0.00%	0.00%
Unrecognized cost of unvested share-based compensation awards.		0		$ 0
Remaining weighted average vesting period				2 years
Internal-use software and website development costs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation capitalized		75,000	$ 225,000
Stock Option Repricing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Financial statement impact amount		100,000
Unamortized expense related to unvested stock-based awards		$ 900,000		$ 900,000
Weighted average vesting period		1 year 10 months 24 days
Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate fair value				$ 3,000
Vesting Period One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percent				25.00%
Vesting period of the options				1 year
Incremental vesting percent				2.08%
Vesting Period One | Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of the options				3 years
Vesting Period Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percent				50.00%
Vesting period of the options				1 year
Incremental vesting percent				2.08%
Vesting Period Two | Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period of the options				4 years
Vesting period three
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percent				50.00%
Vesting period of the options				2 years
Incremental vesting percent				2.08%
Vesting period four
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Incremental vesting percent				2.78%
2015 Stock Option Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options made available in pool (in shares) | shares		60,241,343		60,241,343
Shares available for grant under the plan (in shares) | shares		9,817,115		9,817,115
2005 Stock Plan | Stock options issued and outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under the plan (in shares) | shares		0		0

Shared Based Incentive Plan a71

Shared Based Incentive Plan and Compensation - Summarized Option Activity under Option Plan (Details) - 2005 Stock Plan and 2015 Stock Option Plan	6 Months Ended
	Jun. 30, 2017$ / sharesshares
Options Issued and Outstanding
Options Issued and Outstanding, Beginning Balance (in shares) | shares	41,395,719
Options Issued and Outstanding, Options issued (in shares) | shares	30,388,611
Options Issued and Outstanding, Options exercised - vested (in shares) | shares	(134,633)
Options Issued and Outstanding, Options forfeited (in shares) | shares	(12,089,870)
Options Issued and Outstanding, Options expired (in shares) | shares	(2,500)
Options Issued and Outstanding, Ending balance (in shares) | shares	59,557,327
Options Issued and Outstanding, Options vested and expected to vest (in shares) | shares	47,563,036
Options Issued and Outstanding, Options vested and/or exercisable (in shares) | shares	21,119,436
Weighted- Average Exercise Price
Weighted-Average Exercise Price, Beginning balance (in dollars per share) | $ / shares	$ 1.48
Weighted-Average Exercise Price, Options issued (in dollars per share) | $ / shares	0.22
Weighted-Average Exercise Price, Options exercised - vested (in dollars per share) | $ / shares	0.11
Weighted-Average Exercise Price, Options forfeited (in dollars per share) | $ / shares	1.17
Weighted-Average Exercise Price, Options expired (in dollars per share) | $ / shares	0.22
Weighted-Average Exercise Price, Ending balance (in dollars per share) | $ / shares	0.21
Weighted-Average Exercise Price, Options vested and expected to vest (in dollars per share) | $ / shares	0.21
Weighted-Average Exercise Price, Options vested and/or exercisable (in dollars per share) | $ / shares	$ 0.18

Shared Based Incentive Plan a72

Shared Based Incentive Plan and Compensation - Additional Information Regarding Common Stock Options Outstanding (Details) - Stock options issued and outstanding	6 Months Ended
	Jun. 30, 2017$ / sharesshares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Number Outstanding (in shares) | shares	59,557,327
Weighted Avg. Remaining Life	8 years 8 months 27 days
Weighted Avg. Exercise Price (in dollars per share)	$ 0.20
Number Exercisable (in shares) | shares	21,119,436
Weighted-Avg. Exercise Price (in dollars per share)	$ 0.18
$0.02 - $0.20
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum (in dollars per share)	0.02
Range of Exercise Prices, Maximum (in dollars per share)	$ 0.20
Number Outstanding (in shares) | shares	8,275,145
Weighted Avg. Remaining Life	6 years 6 months 22 days
Weighted Avg. Exercise Price (in dollars per share)	$ 0.11
Number Exercisable (in shares) | shares	8,275,145
Weighted-Avg. Exercise Price (in dollars per share)	$ 0.11
$0.20 - $0.50
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum (in dollars per share)	0.20
Range of Exercise Prices, Maximum (in dollars per share)	$ 0.50
Number Outstanding (in shares) | shares	51,260,062
Weighted Avg. Remaining Life	9 years 1 month 2 days
Weighted Avg. Exercise Price (in dollars per share)	$ 0.22
Number Exercisable (in shares) | shares	12,822,171
Weighted-Avg. Exercise Price (in dollars per share)	$ 0.22
$0.50 - $1.13
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum (in dollars per share)	0.50
Range of Exercise Prices, Maximum (in dollars per share)	$ 1.13
Number Outstanding (in shares) | shares	22,120
Weighted Avg. Remaining Life	7 years 4 months 6 days
Weighted Avg. Exercise Price (in dollars per share)	$ 1.13
Number Exercisable (in shares) | shares	22,120
Weighted-Avg. Exercise Price (in dollars per share)	$ 1.13

Shared Based Incentive Plan a73

Shared Based Incentive Plan and Compensation - Fair Value of Stock Option Awards (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fair value of stock option awards [Abstract]
Volatility of common stock	50.88%	50.28%	50.88%
Risk-free interest rate	1.29%	2.12%	1.29%
Expected life	5 years 9 months 18 days	5 years 8 months 12 days	5 years 9 months 18 days
Dividend yield	0.00%	0.00%	0.00%

Shared Based Incentive Plan a74

Shared Based Incentive Plan and Compensation - Summarized Activities for the Company's RSU's (Details) - Restricted stock units	6 Months Ended
	Jun. 30, 2017$ / sharesshares
Number of Shares
Restricted stock unit, Unvested, Beginning Balance (in shares) | shares	1,995,159
Granted (in shares) | shares	12,000
Vested (in shares) | shares	0
Forfeited (in shares) | shares	(509,479)
Restricted stock unit, Unvested, Ending Balance (in shares) | shares	1,497,680
Weighted-Average Grant Date Fair Value
Restricted stock unit, Unvested, Beginning Balance (in dollars per share) | $ / shares	$ 2.16
Granted (in dollars per share) | $ / shares	0.22
Vested (in dollars per share) | $ / shares	0
Forfeited (in dollars per share) | $ / shares	2.18
Restricted stock unit, Unvested, Ending Balance (in dollars per share) | $ / shares	$ 2.14

Shared Based Incentive Plan a75

Shared Based Incentive Plan and Compensation - Stock Based Compensation Included in Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation	$ 3,312	$ 6,404	$ 6,812	$ 11,510
Origination and servicing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation	328	579	545	1,018
Sales and marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation	141	896	311	1,632
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation	2,843	4,884	5,956	8,815
Restructuring
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation	$ 0	$ 45	$ 0	$ 45

Restructuring - Additional Info

Restructuring - Additional Information (Details) - employee	May 03, 2016	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Terminated employees	167
Israel
Restructuring Cost and Reserve [Line Items]
Terminated employees		31

Restructuring - Summary of Acti

Restructuring - Summary of Activities Related to Prosper's Restructuring Plan (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Restructuring Reserve [Roll Forward]
Balance January 1, 2017	$ 6,649
Adjustments to expense	308
Sublease cash receipts	16
Less: Cash paid	(3,777)
June 30, 2017	3,196
Severance Related
Restructuring Reserve [Roll Forward]
Balance January 1, 2017	597
Adjustments to expense	(13)
Sublease cash receipts	0
Less: Cash paid	(584)
June 30, 2017	0
Facilities Related
Restructuring Reserve [Roll Forward]
Balance January 1, 2017	6,052
Adjustments to expense	321
Sublease cash receipts	16
Less: Cash paid	(3,193)
June 30, 2017	$ 3,196

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Taxes [Line Items]
Income tax expense	$ 97,000	$ 105,000	$ 262,000	$ 270,000
Prosper Funding LLC
Income Taxes [Line Items]
Income tax expense			$ 0	0
Net effective tax rate			0.00%
Valuation ​Allowance of Deferred ​Tax ​Assets
Income Taxes [Line Items]
Income tax expense	$ 0	$ 0	$ 0	$ 0

Consortium Purchase Agreement (

Consortium Purchase Agreement (Details) - Consortium Purchase Agreement $ / shares in Units, $ in Billions	Feb. 27, 2017USD ($)$ / sharesshares
Other Commitments [Line Items]
Commitment to purchase borrower loans (up to) | $	$ 5
Series F Warrant
Other Commitments [Line Items]
Warrant to purchase up to (in shares)	3
Warrant to purchase (number of shares)	177,720,706
Exercise price (in dollars per share) | $ / shares	$ 0.01

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	Jul. 19, 2013USD ($)installment	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Oct. 16, 2008USD ($)
Commitments And Contingencies [Line Items]
Restructuring accrual balance		$ 3,400,000		$ 3,400,000
Rental expense under operating lease arrangements		1,200,000	$ 1,900,000	2,500,000	$ 3,700,000
Designated Amount for loans (less than)		143,500		143,500
Minimum fee, remaining in current year		900,000		900,000
Minimum fee, year two		1,700,000		1,700,000
Minimum fee, year three		900,000		900,000
Minimum liquidity covenant		15,000,000		15,000,000
Purchase of borrower loans		40,900,000
Maximum potential future payments		3,557,000,000		3,557,000,000
Accrued repurchase and indemnification obligation		1,100,000		1,100,000		$ 600,000
Amount of loans sold to lender members									$ 178,000,000
Settlement amount	$ 10,000,000
Number of annual installments paid to plaintiffs | installment	4
Other commitment paid						3,000,000	$ 2,000,000	$ 2,000,000
Settlement installment due in 2017		3,000,000		3,000,000
Prosper Funding LLC
Commitments And Contingencies [Line Items]
Designated Amount for loans (less than)		143,500		143,500
Minimum fee, remaining in current year		1,300,000		1,300,000
Minimum fee, year two		1,700,000		1,700,000
Minimum fee, year three		900,000		900,000
Purchase of borrower loans				40,900,000
Maximum potential future payments		3,506,000,000		3,506,000,000
Accrued repurchase and indemnification obligation		$ 1,000,000		$ 1,000,000		$ 600,000

Commitments and Contingencies81

Commitments and Contingencies - Future Minimum Lease Payments (Details) $ in Thousands	Jun. 30, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remaining six months of 2017	$ 2,762
2,018	5,690
2,019	6,026
2,020	6,193
2,021	6,170
2,022	6,076
Thereafter	8,480
Total future operating lease obligations	$ 41,397

Related Parties - Additional In

Related Parties - Additional Information (Details)	6 Months Ended
	Jun. 30, 2017
Related Party Transactions [Abstract]
Minimum percentage of voting securities considered for related parties	10.00%
Minimum percentage of stock holders considered for related parties	10.00%

Related Parties - Aggregate Amo

Related Parties - Aggregate Amount of Notes Purchased and the Income Earned (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	$ 90	$ 510	$ 184	$ 1,151
Interest Earned on Notes and Borrower Loans	45	70	101	125
Notes and Borrower Loans Balance as of	1,572		1,572		$ 2,157
Prosper Funding LLC
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	5	396	10	801
Interest Earned on Notes and Borrower Loans	35	61	81	110
Notes and Borrower Loans Balance as of	1,012		1,012		1,620
Executive officers and management
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	5	396	10	801
Interest Earned on Notes and Borrower Loans	35	61	81	110
Notes and Borrower Loans Balance as of	1,012		1,012		1,620
Executive officers and management | Prosper Funding LLC
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	5	396	10	801
Interest Earned on Notes and Borrower Loans	35	61	81	110
Notes and Borrower Loans Balance as of	1,012		1,012		1,620
Directors (excluding executive officers and management)
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	85	114	174	350
Interest Earned on Notes and Borrower Loans	10	9	20	15
Notes and Borrower Loans Balance as of	560		560		537
Directors (excluding executive officers and management) | Prosper Funding LLC
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	0	0	0	0
Interest Earned on Notes and Borrower Loans	0	$ 0	0	$ 0
Notes and Borrower Loans Balance as of	$ 0		$ 0		$ 0

Significant Concentrations (Det

Significant Concentrations (Details)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Concentration Risk [Line Items]
Percentage of funds originating in channel	92.00%	92.00%
Party One
Concentration Risk [Line Items]
Percentage of loan purchased	52.00%	25.00%
Party Two
Concentration Risk [Line Items]
Percentage of loan purchased	14.00%	25.00%
Party Three
Concentration Risk [Line Items]
Percentage of loan purchased	8.00%	12.00%