Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net loss	$ (92,007)	$ (6,530)	$ (25,454)	$ (29,844)	$ (32,269)	$ (36,486)	$ (81,351)	$ 4,137	$ (153,835)	$ (145,969)	$ (4,995)
Weighted-average common shares - Basic (shares)	416,005,213	412,778,995	406,676,996	400,308,521	395,877,053	391,453,316	382,893,402	380,266,636	408,995,947	387,762,072	374,872,118
Weighted-average common shares - Diluted (shares)	416,005,213	412,778,995	406,676,996	400,308,521	395,877,053	391,453,316	382,893,402	392,397,825	408,995,947	387,762,072	374,872,118
Net loss per share attributable to LendingClub:
Basic ($ per share)	$ (0.22)	$ (0.02)	$ (0.06)	$ (0.07)	$ (0.08)	$ (0.09)	$ (0.21)	$ 0.01	$ (0.38)	$ (0.38)	$ (0.01)
Diluted ($ per share)	$ (0.22)	$ (0.02)	$ (0.06)	$ (0.07)	$ (0.08)	$ (0.09)	$ (0.21)	$ 0.01	$ (0.38)	$ (0.38)	$ (0.01)