Commitments and Contingencies - Future Minimum Payments under Non-cancelable Operating Leases (Details) $ in Thousands	Jun. 30, 2018 USD ($)
Operating Leases
2018	$ 8,612
2019	16,626
2020	17,557
2021	17,844
2022	13,519
Thereafter	32,644
Total	106,802
Subleases
2018	(155)
2019	(39)
2020	0
2021	0
2022	0
Thereafter	0
Total	(194)
Net
2018	8,457
2019	16,587
2020	17,557
2021	17,844
2022	13,519
Thereafter	32,644
Total	$ 106,608

Operating Leases, Future Minimum Payments Due, Net of Sublease Payments Receivable

No definition available.

Name:	lc_OperatingLeasesFutureMinimumPaymentsDueNetofSubleasePaymentsReceivable
Namespace Prefix:	lc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Operating Leases, Future Minimum Payments, Due Thereafter, Net of Sublease Payments Receivable

+ References

No definition available.

+ Details

Name:	lc_OperatingLeasesFutureMinimumPaymentsDueThereafterNetofSubleasePaymentsReceivable
Namespace Prefix:	lc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Operating Leases, Future Minimum Payments, Due in Five Years, Net of Sublease Payments Receivable

+ References

No definition available.

+ Details

Name:	lc_OperatingLeasesFutureMinimumPaymentsDueinFiveYearsNetofSubleasePaymentsReceivable
Namespace Prefix:	lc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Operating Leases, Future Minimum Payments, Due in Four Years, Net of Sublease Payments Receivable

+ References

No definition available.

+ Details

Name:	lc_OperatingLeasesFutureMinimumPaymentsDueinFourYearsNetofSubleasePaymentsReceivable
Namespace Prefix:	lc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Operating Leases, Future Minimum Payments, Due in Three Years, Net of Sublease Payments Receivable

+ References

No definition available.

+ Details

Name:	lc_OperatingLeasesFutureMinimumPaymentsDueinThreeYearsNetofSubleasePaymentsReceivable
Namespace Prefix:	lc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Operating Leases, Future Minimum Payments, Due in Two Years, Net of Sublease Payments Receivable

+ References

No definition available.

+ Details

Name:	lc_OperatingLeasesFutureMinimumPaymentsDueinTwoYearsNetofSubleasePaymentsReceivable
Namespace Prefix:	lc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Operating Leases, Future Minimum Payments, Remainder of Fiscal Year, Net of Sublease Payments Receivable

+ References

No definition available.

+ Details

Name:	lc_OperatingLeasesFutureMinimumPaymentsRemainderofFiscalYearNetofSubleasePaymentsReceivable
Namespace Prefix:	lc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_FutureMinimumSubleaseRentalsSaleLeasebackTransactionsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 55
-Paragraph 40
-Subparagraph (Note 3)
-URI http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractually required future rental payments receivable on noncancelable subleasing arrangements.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueFutureMinimumSubleaseRentals
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 55
-Paragraph 40
-Subparagraph (Note 3)
-URI http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Future rental payments receivable within the fifth year from the balance sheet date under an operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84164653&loc=d3e41551-112718

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future rental payments receivable within the fourth year from the balance sheet date under an operating lease.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future rental payments receivable within the third year from the balance sheet date under an operating lease.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future rental payments receivable within the second year from the balance sheet date under an operating lease.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of required minimum rental payments receivable in the remainder of the fiscal year following the latest fiscal year ended for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableRemainderOfFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future minimum lease payments receivable under operating leases for periods greater than five years following the balance sheet date.

+ References

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_OperatingLeasesRentExpenseAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration