Securities - Schedule of Marketable Securities in Unrealized Loss Position (Details) $ in Thousands	Jun. 30, 2018 USD ($) security	Dec. 31, 2017 USD ($) security
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	44	36
Available for sale, Less than 12 months Estimated fair value	$ 20,938	$ 29,417
Available for sale, Less than 12 months Unrealized loss	(489)	(294)
Available for sale, 12 months and greater, Estimated fair value	22,516	10,581
Available for sale, 12 months and greater, Unrealized loss	(1,036)	(436)
Available for sale, Total Estimated fair value	43,454	39,998
Available for sale, Total Unrealized loss	$ (1,525)	$ (730)
Held to maturity at cost:
Held to maturity, Total number in a loss position \| security	12	6
Held to maturity, Less than 12 months Estimated fair value	$ 2,550	$ 0
Held to maturity, Less than 12 months Unrealized loss	(26)	0
Held to maturity, 12 months and greater, Estimated fair value	6,989	7,455
Held to maturity, 12 months and greater, Unrealized loss	(342)	(253)
Held to maturity, Total Estimated fair value	9,539	7,455
Held to maturity, Total Unrealized loss	$ (368)	$ (253)
Equity securities:
Equity securities, Total number in a loss position \| security	2
Equity securities, Less than 12 months Estimated Fair Value	$ 0
Equity securities, Less than 12 months Unrealized Loss	0
Equity securities, 12 months and greater, Estimated fair value	906
Equity securities, 12 months and greater, Unrealized loss	(94)
Equity securities, Total Estimated fair value	906
Equity securities, Total Unrealized loss	$ 94
U.S. Government sponsored entities
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	5	5
Available for sale, Less than 12 months Estimated fair value	$ 1,720	$ 3,732
Available for sale, Less than 12 months Unrealized loss	(32)	(40)
Available for sale, 12 months and greater, Estimated fair value	3,878	1,958
Available for sale, 12 months and greater, Unrealized loss	(131)	(34)
Available for sale, Total Estimated fair value	5,598	5,690
Available for sale, Total Unrealized loss	$ (163)	$ (74)
Held to maturity at cost:
Held to maturity, Total number in a loss position \| security	2	2
Held to maturity, Less than 12 months Estimated fair value	$ 0	$ 0
Held to maturity, Less than 12 months Unrealized loss	0	0
Held to maturity, 12 months and greater, Estimated fair value	2,677	2,933
Held to maturity, 12 months and greater, Unrealized loss	(112)	(93)
Held to maturity, Total Estimated fair value	2,677	2,933
Held to maturity, Total Unrealized loss	$ (112)	$ (93)
State and political subdivisions
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	6	2
Available for sale, Less than 12 months Estimated fair value	$ 2,513	$ 476
Available for sale, Less than 12 months Unrealized loss	(72)	(6)
Available for sale, 12 months and greater, Estimated fair value	1,513	1,792
Available for sale, 12 months and greater, Unrealized loss	(108)	(50)
Available for sale, Total Estimated fair value	4,026	2,268
Available for sale, Total Unrealized loss	$ (180)	$ (56)
Residential mortgage-backed securities
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	28	22
Available for sale, Less than 12 months Estimated fair value	$ 13,576	$ 20,646
Available for sale, Less than 12 months Unrealized loss	(345)	(218)
Available for sale, 12 months and greater, Estimated fair value	13,339	4,028
Available for sale, 12 months and greater, Unrealized loss	(596)	(168)
Available for sale, Total Estimated fair value	26,915	24,674
Available for sale, Total Unrealized loss	$ (941)	$ (386)
Held to maturity at cost:
Held to maturity, Total number in a loss position \| security	8	2
Held to maturity, Less than 12 months Estimated fair value	$ 2,550	$ 0
Held to maturity, Less than 12 months Unrealized loss	(26)	0
Held to maturity, 12 months and greater, Estimated fair value	873	979
Held to maturity, 12 months and greater, Unrealized loss	(42)	(18)
Held to maturity, Total Estimated fair value	3,423	979
Held to maturity, Total Unrealized loss	$ (68)	$ (18)
Commercial mortgage-backed securities
Held to maturity at cost:
Held to maturity, Total number in a loss position \| security	2	2
Held to maturity, Less than 12 months Estimated fair value	$ 0	$ 0
Held to maturity, Less than 12 months Unrealized loss	0	0
Held to maturity, 12 months and greater, Estimated fair value	3,439	3,543
Held to maturity, 12 months and greater, Unrealized loss	(188)	(142)
Held to maturity, Total Estimated fair value	3,439	3,543
Held to maturity, Total Unrealized loss	$ (188)	$ (142)
Corporate and other securities
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	5	7
Available for sale, Less than 12 months Estimated fair value	$ 3,129	$ 4,563
Available for sale, Less than 12 months Unrealized loss	(40)	(30)
Available for sale, 12 months and greater, Estimated fair value	3,786	2,803
Available for sale, 12 months and greater, Unrealized loss	(201)	(184)
Available for sale, Total Estimated fair value	6,915	7,366
Available for sale, Total Unrealized loss	$ (241)	$ (214)

Trading Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss

No definition available.

Name:	unty_TradingSecuritiesContinuousUnrealizedLossPosition12MonthsorLongerAccumulatedLoss
Namespace Prefix:	unty_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Trading Securities, Continuous Unrealized Loss Position, Accumulated Loss

+ References

No definition available.

+ Details

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

- Definition

Trading Securities, Continuous Unrealized Loss Position, Fair Value

+ References

No definition available.

+ Details

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

- Definition

Trading Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Accumulated Loss

+ References

No definition available.

+ Details

Name:	unty_TradingSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix:	unty_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Trading Securities, Continuous Unrealized Loss Position, Less Than Twelve Months, Fair Value

+ References

No definition available.

+ Details

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

- Definition

Trading Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value

+ References

No definition available.

+ Details

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

- Definition

Trading Securities, Securities In Unrealized Loss Positions, Qualitative Disclosure, Number Of Positions

+ References

No definition available.

+ Details

Name:	unty_TradingSecuritiesSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
Namespace Prefix:	unty_
Data Type:	xbrli:decimalItemType
Balance Type:	na
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 of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

+ Details

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

- Definition

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References

+ Details

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

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months.

+ References

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

+ Details

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

- Definition

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

+ Details

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

- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

+ Details

Name:	us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
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 loss on investments in debt securities classified as held-to-maturity that have been in a continuous loss position for twelve months or longer.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

+ Details

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

- Definition

This item represents the fair value of securities categorized as held-to-maturity which are in an unrealized loss position.

+ References

+ Details

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

- Definition

Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity that have been in a continuous loss position for less than twelve months.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the fair value of securities categorized as held-to-maturity that have been in a continuous unrealized loss position for less than twelve months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

+ Details

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

- Definition

This item represents the fair value of securities categorized as held-to-maturity securities that have been in a continuous unrealized loss position for twelve months or longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

+ Details

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

- Definition

Disclosure regarding factors used to determine that the impairment of securities categorized as held-to-maturity where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the held-to-maturity investments determined to be temporarily impaired.

+ References

+ Details

Name:	us-gaap_HeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
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

- 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: