10. Business Segments (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Net interest income	$ 7,331,000	$ 7,075,000	$ 14,435,000	$ 13,903,000
Service charges on deposits	335,000	272,000	651,000	506,000
Investment services and insurance income	187,000	(29,000)	361,000	65,000
Mortgage banking income, net	613,000	752,000	1,113,000	1,196,000
Title insurance income	355,000	0	554,000	0
Income from bank owned life insurance	112,000	118,000	224,000	237,000
Low income housing partnership losses	(201,000)	(183,000)	(386,000)	(365,000)
ATM and check card fees	351,000	318,000	681,000	692,000
Gain on prepayment of long-term debt			(504,000)	0
Other operating income	130,000	130,000	268,000	250,000
Expenses:
Interest Expense	925,000	862,000	1,831,000	1,675,000
Provision for loan losses	0	0	0	0
Salary expense	2,628,000	2,133,000	5,362,000	4,543,000
Employee benefit expense	852,000	661,000	1,805,000	1,414,000
Occupancy expense	254,000	210,000	503,000	428,000
Equipment expense	207,000	230,000	393,000	422,000
FDIC insurance assessment	90,000	113,000	180,000	225,000
Marketing expense	122,000	131,000	257,000	268,000
Legal and professional fees	79,000	105,000	175,000	193,000
ATM and check card fees	178,000	172,000	346,000	333,000
Telecom and data processing expense	352,000	289,000	675,000	552,000
Directors fees	116,000	100,000	243,000	208,000
Bank franchise Tax	164,000	163,000	324,000	310,000
Income tax expense	809,000	839,000	1,686,000	1,533,000
Net income (loss)	2,387,000	2,444,000	4,705,000	4,538,000
Total Assets	744,263,000		744,263,000		$ 744,889,000
Goodwill	2,974,000		2,974,000		$ 2,670,000
F&M Bank Member
Net interest income	8,209,919	7,893,961	16,170,387	15,492,768
Service charges on deposits	335,382	272,329	650,718	506,028
Investment services and insurance income	489	163	585	508
Mortgage banking income, net	0	0	0	0
Title insurance income	0	0	0	0
Income from bank owned life insurance	111,455	118,068	223,711	236,652
Low income housing partnership losses	(200,813)	(182,694)	(386,142)	(365,387)
ATM and check card fees	351,505	318,287	681,448	692,194
Gain on prepayment of long-term debt	0	0	503,830	0
Loss on investments	0	0	0	0
Other operating income	129,815	129,743	268,370	249,751
Total income	8,937,752	8,549,857	18,112,967	16,812,514
Expenses:
Interest Expense	926,890	863,306	1,834,272	1,678,349
Provision for loan losses	0	0	0	0
Salary expense	2,260,954	1,940,505	4,453,744	4,023,139
Employee benefit expense	707,438	602,158	1,523,051	1,299,406
Occupancy expense	202,205	179,648	403,120	367,578
Equipment expense	189,060	170,651	359,175	354,155
FDIC insurance assessment	90,000	112,500	180,000	225,000
Other real estate owned, net	11,843	35,142	25,608	52,841
Marketing expense	99,963	118,924	216,205	234,904
Legal and professional fees	76,663	102,037	170,299	188,310
ATM and check card fees	176,934	170,791	344,257	330,966
Telecom and data processing expense	325,679	266,194	624,886	509,256
Directors fees	105,000	96,000	210,000	192,000
Bank franchise Tax	164,249	162,643	324,255	310,303
Other operating expenses	717,539	655,378	1,360,275	1,254,784
Total expense	6,054,417	5,475,877	12,029,147	11,020,991
Income tax expense	800,944	878,180	1,669,606	1,582,813
Net income (loss)	2,082,391	2,195,800	4,414,214	4,208,710
Net income (loss) attributable to noncontrolling interest	0	0	0	0
Net Income attributable to F & M Bank Corp.	2,082,391	2,195,800	4,414,214	4,208,710
Total Assets	746,193,130	733,417,958	746,193,130	733,417,958
Goodwill	2,669,517	2,669,517	2,669,517	2,669,517
VBS Mortgage
Net interest income	30,051	6,885	65,347	13,213
Service charges on deposits	0	0	0	0
Investment services and insurance income	0	0	0	0
Mortgage banking income, net	612,594	751,388	1,112,521	1,196,444
Title insurance income	0	0	0	0
Income from bank owned life insurance	0	0	0	0
Low income housing partnership losses	0	0	0	0
ATM and check card fees	0	0	0	0
Gain on prepayment of long-term debt	0	0	0	0
Loss on investments	0	0	(39,474)	0
Other operating income	0	0	0	0
Total income	642,645	758,273	1,138,394	1,209,657
Expenses:
Interest Expense	20,123	0	41,268	0
Provision for loan losses	0	0	0	0
Salary expense	129,586	117,122	449,573	380,298
Employee benefit expense	81,160	58,833	166,785	114,529
Occupancy expense	36,398	30,150	66,596	60,471
Equipment expense	9,587	59,690	18,903	68,137
FDIC insurance assessment	0	0	0	0
Other real estate owned, net	0	0	0	0
Marketing expense	17,339	12,169	33,850	32,593
Legal and professional fees	2,475	2,574	4,725	5,049
ATM and check card fees	990	1,571	1,923	2,155
Telecom and data processing expense	26,345	22,537	50,513	42,828
Directors fees	11,334	3,500	33,334	15,500
Bank franchise Tax	0	0	0	0
Other operating expenses	215,934	154,862	260,440	187,519
Total expense	551,271	463,008	1,127,910	909,079
Income tax expense	0	0	0	0
Net income (loss)	91,374	295,265	10,484	300,578
Net income (loss) attributable to noncontrolling interest	27,412	86,410	3,145	90,173
Net Income attributable to F & M Bank Corp.	63,982	208,855	7,339	210,405
Total Assets	6,027,200	2,296,877	6,027,200	2,296,877
Goodwill	0	0	0	0
TEB Life/FMFS
Net interest income	37,719	37,914	74,993	75,030
Service charges on deposits	0	0	0	0
Investment services and insurance income	186,625	(29,057)	360,416	64,830
Mortgage banking income, net	0	0	0	0
Title insurance income	0	0	0	0
Income from bank owned life insurance	0	0	0	0
Low income housing partnership losses	0	0	0	0
ATM and check card fees	0	0	0	0
Gain on prepayment of long-term debt	0	0	0	0
Loss on investments	0	0	(2,440)	0
Other operating income	0	0	0	0
Total income	224,344	8,857	432,969	139,860
Expenses:
Interest Expense	0	0	0	0
Provision for loan losses	0	0	0	0
Salary expense	118,650	75,767	234,209	139,463
Employee benefit expense	0	0	0	0
Occupancy expense	0	0	0	0
Equipment expense	0	0	0	0
FDIC insurance assessment	0	0	0	0
Other real estate owned, net	0	0	0	0
Marketing expense	3,910	198	4,315	549
Legal and professional fees	0	0	0	0
ATM and check card fees	0	0	0	0
Telecom and data processing expense	0	0	0	0
Directors fees	0	0	0	0
Bank franchise Tax	0	0	0	0
Other operating expenses	9,453	18,456	12,844	21,051
Total expense	132,013	94,421	251,368	161,063
Income tax expense	26,172	12,321	52,842	31,828
Net income (loss)	66,159	(97,885)	128,759	(53,031)
Net income (loss) attributable to noncontrolling interest	0	0	0	0
Net Income attributable to F & M Bank Corp.	66,159	(97,885)	128,759	(53,031)
Total Assets	6,630,313	6,328,376	6,630,313	6,328,376
Goodwill	0	0	0	0
VS Title
Net interest income	0	0	0	0
Service charges on deposits	0	0	0	0
Investment services and insurance income	0	0	0	0
Mortgage banking income, net	0	0	0	0
Title insurance income	355,351	0	553,897	0
Income from bank owned life insurance	0	0	0	0
Low income housing partnership losses	0	0	0	0
ATM and check card fees	0	0	0	0
Gain on prepayment of long-term debt	0	0	0	0
Loss on investments	0	0	0	0
Other operating income	0	0	0	0
Total income	355,351	0	553,897	0
Expenses:
Interest Expense	0	0	0	0
Provision for loan losses	0	0	0	0
Salary expense	118,846	0	224,572	0
Employee benefit expense	63,226	0	114,808	0
Occupancy expense	15,645	0	33,505	0
Equipment expense	8,353	0	15,039	0
FDIC insurance assessment	0	0	0	0
Other real estate owned, net	0	0	0	0
Marketing expense	791	0	2,536	0
Legal and professional fees	0	0	0	0
ATM and check card fees	0	0	0	0
Telecom and data processing expense	0	0	0	0
Directors fees	0	0	0	0
Bank franchise Tax	0	0	0	0
Other operating expenses	18,064	0	44,099	0
Total expense	224,925	0	434,559	0
Income tax expense	0	0	0	0
Net income (loss)	130,426	0	119,338	0
Net income (loss) attributable to noncontrolling interest	31,302	0	28,641	0
Net Income attributable to F & M Bank Corp.	99,124	0	90,697	0
Total Assets	274,400	0	274,400	0
Goodwill	0	0	0	0
Parent Only
Net interest income	0	0	13	0
Service charges on deposits	0	0	0	0
Investment services and insurance income	0	0	0	0
Mortgage banking income, net	0	0	0	0
Title insurance income	0	0	0	0
Income from bank owned life insurance	0	0	0	0
Low income housing partnership losses	0	0	0	0
ATM and check card fees	0	0	0	0
Gain on prepayment of long-term debt	0	0	0	0
Loss on investments	0	0	0	0
Other operating income	0	0	0	0
Total income	0	0	13	0
Expenses:
Interest Expense	0	0	0	0
Provision for loan losses	0	0	0	0
Salary expense	0	0	0	0
Employee benefit expense	0	0	0	0
Occupancy expense	0	0	0	0
Equipment expense	0	0	0	0
FDIC insurance assessment	0	0	0	0
Other real estate owned, net	0	0	0	0
Marketing expense	0	0	0	0
Legal and professional fees	0	0	0	0
ATM and check card fees	0	0	0	0
Telecom and data processing expense	0	0	0	0
Directors fees	0	0	0	0
Bank franchise Tax	0	0	0	0
Other operating expenses	1,125	200	3,825	400
Total expense	1,125	200	3,825	400
Income tax expense	(17,717)	(51,556)	(35,968)	(81,993)
Net income (loss)	16,592	51,356	32,156	81,593
Net income (loss) attributable to noncontrolling interest	0	0	0
Net Income attributable to F & M Bank Corp.	16,592	51,356	32,156	81,593
Total Assets	89,908,521	86,082,770	89,908,521	86,082,770
Goodwill	304,000	0	304,000	0
Eliminations
Net interest income	(22,052)	(1,550)	(44,763)	(3,037)
Service charges on deposits	0	0	0	0
Investment services and insurance income	0	0	0	0
Mortgage banking income, net	0	0	0	0
Title insurance income	0	0	0	0
Income from bank owned life insurance	0	0	0	0
Low income housing partnership losses	0	0	0	0
ATM and check card fees	0	0	0	0
Gain on prepayment of long-term debt	0	0	0	0
Loss on investments	0	0	0	0
Other operating income	0	0	0	0
Total income	(22,052)	(1,550)	(44,763)	(3,037)
Expenses:
Interest Expense	(22,052)	(1,550)	(44,763)	(3,037)
Provision for loan losses	0	0	0	0
Salary expense	0	0	0	0
Employee benefit expense	0	0	0	0
Occupancy expense	0	0	0	0
Equipment expense	0	0	0	0
FDIC insurance assessment	0	0	0	0
Other real estate owned, net	0	0	0	0
Marketing expense	0	0	0	0
Legal and professional fees	0	0	0	0
ATM and check card fees	0	0	0	0
Telecom and data processing expense	0	0	0	0
Directors fees	0	0	0	0
Bank franchise Tax	0	0	0	0
Other operating expenses	0	0	0	0
Total expense	(22,052)	(1,550)	(44,763)	(3,037)
Income tax expense	0	0	0	0
Net income (loss)	0	0	0	0
Net income (loss) attributable to noncontrolling interest	0	0	0	0
Net Income attributable to F & M Bank Corp.	0	0	0	0
Total Assets	(104,770,806)	(98,088,075)	(104,770,806)	(98,088,075)
Goodwill	0	0	0	0
F&M Bank Corp Consolidated
Net interest income	8,255,637	7,937,210	16,265,977	15,577,974
Service charges on deposits	335,382	272,329	650,718	506,028
Investment services and insurance income	187,114	(28,894)	361,001	65,338
Mortgage banking income, net	612,594	751,388	1,112,521	1,196,444
Title insurance income	355,351	0	553,897	0
Income from bank owned life insurance	111,455	118,068	223,771	236,652
Low income housing partnership losses	(200,813)	(182,694)	(386,142)	(365,387)
ATM and check card fees	351,505	318,287	681,448	692,194
Gain on prepayment of long-term debt	0	0	503,830	0
Loss on investments	0	0	(41,914)	0
Other operating income	129,815	129,743	268,370	249,751
Total income	10,138,040	9,315,437	20,193,477	18,158,994
Expenses:
Interest Expense	924,961	861,756	1,830,777	1,675,312
Provision for loan losses	0	0	0	0
Salary expense	2,628,036	2,133,394	5,362,098	4,542,900
Employee benefit expense	851,824	660,991	1,804,644	1,413,935
Occupancy expense	254,248	209,798	503,221	428,049
Equipment expense	207,000	230,341	393,117	422,292
FDIC insurance assessment	90,000	112,500	180,000	225,000
Other real estate owned, net	11,843	35,142	25,608	52,841
Marketing expense	122,003	131,291	256,906	268,046
Legal and professional fees	79,138	104,611	175,024	193,359
ATM and check card fees	177,924	172,362	346,180	333,121
Telecom and data processing expense	352,024	288,731	675,399	552,084
Directors fees	116,334	99,500	243,334	207,500
Bank franchise Tax	164,249	162,643	324,255	310,303
Other operating expenses	962,115	828,896	1,681,483	1,463,754
Total expense	6,941,699	6,031,956	13,802,046	12,088,496
Income tax expense	809,399	838,945	1,686,480	1,532,648
Net income (loss)	2,386,942	2,444,536	4,704,951	4,537,850
Net income (loss) attributable to noncontrolling interest	58,714	86,410	31,786	90,173
Net Income attributable to F & M Bank Corp.	2,328,228	2,358,126	4,673,165	4,447,677
Total Assets	744,262,758	730,037,906	744,262,758	730,037,906
Goodwill	$ 2,973,517	$ 2,669,517	$ 2,973,517	$ 2,669,517