| **Audit Information**            | 12 Months Ended       |
|----------------------------------|-----------------------|
||
| **Audit Information [Abstract]** |                  |
| Auditor Name                     | DELOITTE & TOUCHE LLP |
| Auditor Location                 | Chicago, Illinois     |
| Auditor Firm ID                  | 34                    |

| X                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Audit Information
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
PCAOB issued Audit Firm Identifier
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form 10-K -Number 249 -Section 310Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form 20-F -Number 249 -Section 220 -Subsection fReference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form 40-F -Number 249 -Section 240 -Subsection f
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form 10-K -Number 249 -Section 310Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form 20-F -Number 249 -Section 220 -Subsection fReference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form 40-F -Number 249 -Section 240 -Subsection f
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form 10-K -Number 249 -Section 310Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form 20-F -Number 249 -Section 220 -Subsection fReference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form 40-F -Number 249 -Section 240 -Subsection f
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