Basis of Presentation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015
Property Plant And Equipment [Line Items]
Reclassification of signage revenue from fee and other income to property rentals	$ 9,300

The amount of a reclassification adjustment made to prior period financial statement amounts.

No definition available.

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