Securities - Reconciliation from Amortized Cost to Estimated Fair Value of Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Available for sale at fair value:
Amortized cost	$ 50,133	$ 52,763
Gross unrealized gains	99	183
Gross unrealized losses	(1,525)	(659)
Securities available for sale	48,707	52,287
Held to maturity at cost:
Amortized cost	15,777	16,307
Gross unrealized gains	205	292
Gross unrealized losses	(368)	(253)
Estimated fair value	15,614	16,346
Equity securities:
Amortized cost	1,262	1,262
Gross unrealized gains	30	15
Gross unrealized losses	(94)	(71)
Estimated fair value	1,198	1,206
U.S. Government sponsored entities
Available for sale at fair value:
Amortized cost	5,761	5,765
Gross unrealized gains	0	0
Gross unrealized losses	(163)	(74)
Securities available for sale	5,598	5,691
Held to maturity at cost:
Amortized cost	2,789	3,026
Gross unrealized gains	0	0
Gross unrealized losses	(112)	(93)
Estimated fair value	2,677	2,933
State and political subdivisions
Available for sale at fair value:
Amortized cost	5,001	5,227
Gross unrealized gains	1	21
Gross unrealized losses	(180)	(56)
Securities available for sale	4,822	5,192
Held to maturity at cost:
Amortized cost	1,113	1,113
Gross unrealized gains	109	144
Gross unrealized losses	0	0
Estimated fair value	1,222	1,257
Residential mortgage-backed securities
Available for sale at fair value:
Amortized cost	29,715	32,111
Gross unrealized gains	79	153
Gross unrealized losses	(941)	(386)
Securities available for sale	28,853	31,878
Held to maturity at cost:
Amortized cost	3,727	3,958
Gross unrealized gains	19	59
Gross unrealized losses	(68)	(18)
Estimated fair value	3,678	3,999
Commercial mortgage-backed securities
Held to maturity at cost:
Amortized cost	3,628	3,685
Gross unrealized gains	0	0
Gross unrealized losses	(188)	(142)
Estimated fair value	3,440	3,543
Corporate and other securities
Available for sale at fair value:
Amortized cost	9,656	9,660
Gross unrealized gains	19	9
Gross unrealized losses	(241)	(143)
Securities available for sale	9,434	9,526
Held to maturity at cost:
Amortized cost	4,520	4,525
Gross unrealized gains	77	89
Gross unrealized losses	0	0
Estimated fair value	$ 4,597	$ 4,614

Debt Securities, Available-For-Sale

No definition available.

Name:	unty_DebtSecuritiesAvailableForSale
Namespace Prefix:	unty_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

No definition available.

+ Details

Name:	unty_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix:	unty_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt Securities, Available-For-Sale, Accumulated Gross Unrealized Loss, Before Tax

+ References

No definition available.

+ Details

Name:	unty_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix:	unty_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

No definition available.

+ Details

Name:	unty_DebtSecuritiesAvailableForSaleAmortizedCost
Namespace Prefix:	unty_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Trading Securities, Accumulated Unrecognized Holding Gain

+ References

No definition available.

+ Details

Name:	unty_TradingSecuritiesAccumulatedUnrecognizedHoldingGain
Namespace Prefix:	unty_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Trading Securities, Accumulated Unrecognized Holding Loss

+ References

No definition available.

+ Details

Name:	unty_TradingSecuritiesAccumulatedUnrecognizedHoldingLoss
Namespace Prefix:	unty_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75030427&loc=d3e22054-111558

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.6)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_HeldToMaturitySecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of accumulated unrealized gain on investments in debt securities classified as held-to-maturity.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value of investments in debt securities classified as held-to-maturity.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_TradingSecuritiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of investments in trading equity securities and other forms of trading securities that provide ownership interests.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26626-111562

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26610-111562

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.(a),1(b))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_TradingSecuritiesEquity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cost of investments in equity securities and other forms of securities that provide ownership interests classified as trading.

+ References

No definition available.

+ Details

Name:	us-gaap_TradingSecuritiesEquityCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: