Non-Qualified Deferred Compensation Plan (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2015	Dec. 31, 2014
Non Qualified Deferred Compensation Plan [Abstract]
Document Period End Date	Jun. 30, 2015
Deferred compensation liability included in accounts payable and other liabilities	$ 29.0	$ 27.6

The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.

No definition available.

Name:	dei_DocumentPeriodEndDate
Namespace Prefix:	dei_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration