Subsequent Events (Details) (USD $)	9 Months Ended	1 Months Ended
Sep. 30, 2011	Oct. 31, 2011 Acquisitions [Member]	Nov. 02, 2011 Dividend Declared [Member]
Subsequent Event [Line Items]
Subsequent event, description		we completed the acquisitions of Pacific Real Estate Partners “PREP” and DST International Property Services “DST”
Dividends declared (in dollars per share)	$ 0.15		$ 0.15
Dividend payment, date			Dec. 15, 2011
Dividend payment, holders of record			Nov. 15, 2011

Date of subsequent event occurrence or of indication that subsequent event occurred.

Name:	jll_DateOfSubsequentEvent
Namespace Prefix:	jll
Data Type:	invest:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The date as of when a holder must own the stock to be entitled to the dividend. The ex-dividend date is generally 3 days before the record date.

+ Details

Name:	us-gaap_DividendsPayableDateOfRecordDayMonthAndYear
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.

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date of subsequent event occurrence or of indication that subsequent event occurred.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 855

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

+ Details

Name:	us-gaap_SubsequentEventsDate
Namespace Prefix:	us-gaap
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration