Interest Rate Swaps - Summary of Interest Rate Swap Agreements (Detail) - USD ($)	3 Months Ended
Jun. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Fair Value	$ 1,094,000	$ 2,045,000
Interest Rate Swap 1
Derivative [Line Items]
Fair Value	$ 400,000
Derivative Financial Instruments, Liabilities \| Interest Rate Swap 5
Derivative [Line Items]
Interest rate swap agreement, effective date	Aug. 14, 2015
Interest rate swap agreement, maturity date	Dec. 14, 2018
Interest Strike Rate	1.79%
Fair Value	$ 255,000	529,000
Current Notional Value	$ 50,000,000	50,000,000
Derivative Financial Instruments, Liabilities \| Interest Rate Swap 3
Derivative [Line Items]
Interest rate swap agreement, effective date	Jan. 15, 2015
Interest rate swap agreement, maturity date	Feb. 15, 2019
Interest Strike Rate	1.826%
Fair Value	$ 175,000	338,000
Current Notional Value	$ 30,000,000	30,000,000
Derivative Financial Instruments, Liabilities \| Interest Rate Swap 4
Derivative [Line Items]
Interest rate swap agreement, effective date	Jul. 15, 2015
Interest rate swap agreement, maturity date	Feb. 15, 2019
Interest Strike Rate	2.01%
Fair Value	$ 253,000	440,000
Current Notional Value	$ 29,282,000	29,674,000
Derivative Financial Instruments, Liabilities \| Interest Rate Swap Six [Member]
Derivative [Line Items]
Interest rate swap agreement, effective date	Feb. 16, 2016
Interest rate swap agreement, maturity date	Dec. 14, 2018
Interest Strike Rate	2.005%
Fair Value	$ 411,000	738,000
Current Notional Value	$ 50,000,000	50,000,000
Derivative Financial Instruments, Assets [Member] \| Interest Rate Swap 1
Derivative [Line Items]
Interest rate swap agreement, effective date	Feb. 14, 2018
Interest rate swap agreement, maturity date	Jan. 14, 2022
Interest Strike Rate	1.349%
Fair Value	$ 2,588,000	3,245,000
Current Notional Value	$ 0	0
Derivative Financial Instruments, Assets [Member] \| Interest Rate Swap 2
Derivative [Line Items]
Interest rate swap agreement, effective date	Aug. 14, 2018
Interest rate swap agreement, maturity date	Jan. 14, 2022
Interest Strike Rate	1.406%
Fair Value	$ 1,811,000	2,349,000
Current Notional Value	$ 0	$ 0

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Date the entity entered into the derivative contract, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeInceptionDates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Date the derivative contract matures, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeMaturityDates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13433-108611

+ Details

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

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=rexr_InterestRateSwapOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=rexr_InterestRateSwapFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=rexr_InterestRateSwapThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=rexr_InterestRateSwapFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=rexr_InterestRateSwapSixMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_DerivativeFinancialInstrumentsAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=rexr_InterestRateSwapTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: