Orrstown Financial Services, Inc. (Parent Company Only) Financial Information - Condensed Statements of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income (loss)	$ 29,142us-gaap_NetIncomeLoss	$ 10,004us-gaap_NetIncomeLoss	$ (38,454)us-gaap_NetIncomeLoss
Adjustments to reconcile net income (loss) to cash used in operating activities:
Deferred income taxes	(16,223)	0	20,384
Losses on sale of investment securities	(1,935)us-gaap_GainLossOnSaleOfSecuritiesNet	(332)us-gaap_GainLossOnSaleOfSecuritiesNet	(4,824)us-gaap_GainLossOnSaleOfSecuritiesNet
Share-based compensation	190us-gaap_ShareBasedCompensation	129us-gaap_ShareBasedCompensation	23us-gaap_ShareBasedCompensation
Other, net	1,629	12,356	(13,516)
Net cash provided by operating activities	17,258	32,960	18,658
Cash flows from investing activities:
Sales of securities available for sale	169,573	74,273	94,099
Maturities of available for sale securities	41,520	86,581	85,481
Net cash provided by (used in) investing activities	727	(89,681)	195,726
Cash flows from financing activities:
Proceeds from issuance of common stock	105	253	189
Net cash used in financing activities	(24,136)	(56,407)	(173,365)
Net decrease in cash	(6,151)	(113,128)	41,019
Cash and cash equivalents at beginning of year	37,560	150,688	109,669
Cash and cash equivalents at end of year	31,409	37,560	150,688
Parent Company [Member]
Cash flows from operating activities:
Net income (loss)	29,142	10,004	(38,454)
Adjustments to reconcile net income (loss) to cash used in operating activities:
Deferred income taxes	(25)	0	0
Gains on affiliate dissolution	(54)	0	0
Losses on sale of investment securities	0	0	101
Equity in undistributed (income) loss of bank subsidiary	(29,932)	(11,019)	37,487
Share-based compensation	17	129	23
Net change in other liabilities	(26)	62	35
Other, net	(270)	(182)	210
Net cash provided by operating activities	(1,148)	(1,006)	(598)
Cash flows from investing activities:
Sales of securities available for sale	0	0	1,109
Maturities of available for sale securities	0	0	1,895
Investment in bank subsidiary	(161)	0	(4,000)
Other	89	0	0
Net cash provided by (used in) investing activities	(72)	0	(996)
Cash flows from financing activities:
Dividends paid	0	0	0
Proceeds from issuance of common stock	105	253	189
Net cash used in financing activities	105	253	189
Net decrease in cash	(1,115)	(753)	(1,405)
Cash and cash equivalents at beginning of year	1,504	2,257	3,662
Cash and cash equivalents at end of year	$ 389	$ 1,504	$ 2,257

Income loss from equity undistributed bank subsidiary.

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