ORRSTOWN FINANCIAL SERVICES, INC. (PARENT COMPANY ONLY) CONDENSED FINANCIAL INFORMATION - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash in Orrstown Bank	$ 25,969	$ 26,156
Other assets	46,921	29,947
Total assets	2,383,274	1,934,388
Subordinated Debt	31,847	31,859
Other liabilities	34,720	22,821
Total liabilities	2,160,025	1,760,955
Shareholders’ Equity
Common stock	584	491
Additional paid-in capital	188,365	151,678
Retained earnings	35,246	24,472
Accumulated other comprehensive income (loss)	(480)	(2,972)
Treasury stock	(466)	(236)
Total shareholders’ equity	223,249	173,433	$ 144,765	$ 134,859
Total liabilities and shareholders’ equity	2,383,274	1,934,388
Consolidated
Assets
Cash in Orrstown Bank	11,568	28,596
Investment in Orrstown Bank	242,041	175,299
Other assets	1,724	2,057
Total assets	255,333	205,952
Subordinated Debt	31,847	31,859
Other liabilities	237	660
Total liabilities	32,084	32,519
Shareholders’ Equity
Common stock	584	491
Additional paid-in capital	188,365	151,678
Retained earnings	35,246	24,472
Accumulated other comprehensive income (loss)	(480)	(2,972)
Treasury stock	(466)	(236)
Total shareholders’ equity	223,249	173,433
Total liabilities and shareholders’ equity	$ 255,333	$ 205,952