Parent Company Only Financial Statements - Income Statement (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Income Statements, Captions [Line Items]
Interest income		$ 288,408,000	$ 227,980,000	$ 162,643,000
Interest expense		93,685,000	87,898,000	54,600,000
Net interest income		194,723,000	140,082,000	108,043,000
Other noninterest income		14,010,000	7,996,000	7,671,000
Total noninterest income	$ 20,125,000	86,000,000	63,519,000	96,265,000
Noninterest expense
Salaries and employee benefits		112,525,000	90,634,000	77,411,000
Professional services expense		6,359,000	6,859,000	4,878,000
Renewable energy tax credit investment impairment		0	602,000	0
Impairment expense on goodwill and other intangibles, net		0	0	2,680,000
Other expense		9,864,000	7,545,000	9,652,000
Total noninterest expense		192,676,000	164,924,000	152,704,000
Income before taxes		47,389,000	23,465,000	46,046,000
Income tax benefit		(12,154,000)	5,431,000	(5,402,000)
Net income	$ 6,832,000	59,543,000	18,034,000	51,448,000
Live Oak Bancshares, Inc.
Condensed Income Statements, Captions [Line Items]
Interest income		91,000	236,000	46,000
Interest expense		372,000		129,000
Net interest income		(281,000)	236,000	(83,000)
Other noninterest income		252,000	140,000	562,000
Total noninterest income		252,000	140,000	562,000
Noninterest expense
Salaries and employee benefits		17,250,000	12,408,000	10,117,000
Professional services expense		750,000	825,000	853,000
Renewable energy tax credit investment impairment			602,000
Impairment expense on goodwill and other intangibles, net				2,680,000
Other expense		1,167,000	999,000	1,844,000
Total noninterest expense		19,167,000	14,834,000	15,494,000
Income before taxes		(19,196,000)	(14,458,000)	(15,015,000)
Income tax benefit		(7,785,000)	(27,000)	(3,658,000)
Net loss		(11,411,000)	(14,431,000)	(11,357,000)
Equity in undistributed income of subsidiaries in excess of dividends from subsidiaries		70,954,000	32,465,000	62,805,000
Net income		$ 59,543,000	$ 18,034,000	$ 51,448,000