XML 59 R41.htm IDEA: XBRL DOCUMENT v3.8.0.1

Summary of Significant Accounting Policies - Business Acquisitions (Details) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Oct. 05, 2017	Sep. 02, 2016 Lot Home
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired			$ 4.1	$ 82.2	$ 70.9
Wilson Parker Homes [Member]
Business Acquisition [Line Items]
Business Acquisition, Date of Acquisition Agreement		Sep. 02, 2016
Payments to Acquire Businesses, Net of Cash Acquired		$ 91.9
Business Acquisition, Number of Homes Acquired | Home							380
Business Acquisition, Number of Finished Lots Acquired | Lot							490
Business Acquisition, Number of Lots Under Option Contracts | Lot							1,850
Business Acquisition, Sales Order Backlog Acquired (Homes) | Home							308
Goodwill, Acquired During Period		$ 0.0
Subsequent Event [Member] | Forestar Group [Member]
Business Acquisition [Line Items]
Business Acquisition, Date of Acquisition Agreement	Oct. 05, 2017
Payments to Acquire Businesses, Net of Cash Acquired	$ 558.3
Business Acquisition, Percentage of Voting Interests Acquired						75.00%

X

- Definition

The number of finished lots purchased through a business acquisition.

+ References

No definition available.

+ Details

Name:	dhi_BusinessAcquisitionNumberOfFinishedLotsAcquired
Namespace Prefix:	dhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The number of homes acquired by the entity through a business acquisition.

+ References

No definition available.

+ Details

Name:	dhi_BusinessAcquisitionNumberofHomesAcquired
Namespace Prefix:	dhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The number of lots the entity controls through option contracts as a result of a business acquisition.

+ References

No definition available.

+ Details

Name:	dhi_BusinessAcquisitionNumberofLotsUnderOptionContracts
Namespace Prefix:	dhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The sales order backlog (homes) acquired by the entity through a business acquisition.

+ References

No definition available.

+ Details

Name:	dhi_BusinessAcquisitionSalesOrderBacklogAcquiredHomes
Namespace Prefix:	dhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Date when the business acquisition agreement was executed, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionDateOfAcquisitionAgreement1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

X

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

X

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

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

X

- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=dhi_WilsonParkerHomesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=dhi_ForestarGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: