Condensed Financial Information of Fidelity Southern Corporation (Parent Company Only) - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets
Other assets	$ 59,215	$ 69,145
Total assets	4,576,858	4,389,685
Liabilities
Other liabilities	36,859	32,639
Total liabilities	4,175,226	4,027,038
Shareholders’ Equity
Preferred stock	0	0
Common stock	217,555	205,309
Accumulated other comprehensive income	383	692
Retained earnings	183,694	156,646
Total shareholders’ equity	401,632	362,647	$ 301,459	$ 264,951
Total liabilities and shareholders’ equity	4,576,858	4,389,685
Parent Company
Assets
Cash held at bank subsidiary	9,121	6,659	$ 4,011	$ 4,964
Land	109	109
Investment in bank subsidiary	423,034	386,444
Investments in and amounts due from non-bank subsidiaries	2,121	3,124
Subordinated loan to bank subsidiary	10,000	10,000
Other assets	3,689	2,829
Total assets	448,074	409,165
Liabilities
Subordinated debt	46,389	46,380
Other liabilities	53	138
Total liabilities	46,442	46,518
Shareholders’ Equity
Preferred stock	0	0
Common stock	217,555	205,309
Accumulated other comprehensive income	383	692
Retained earnings	183,694	156,646
Total shareholders’ equity	401,632	362,647
Total liabilities and shareholders’ equity	$ 448,074	$ 409,165