Investment in Office and Parking Properties - Schedule of Gross Purchase Price (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Business Acquisition [Line Items]
Total Purchase Price	$ 862,475
Atlanta, Georgia
Business Acquisition [Line Items]
Total Purchase Price	47,000
Austin, Texas
Business Acquisition [Line Items]
Total Purchase Price	311,400
Orlando, Florida
Business Acquisition [Line Items]
Total Purchase Price	33,300
Orlando, Florida
Business Acquisition [Line Items]
Total Purchase Price	80,611
Miami, Florida
Business Acquisition [Line Items]
Total Purchase Price	140,495
Tampa, Florida
Business Acquisition [Line Items]
Total Purchase Price	$ 249,669