Subsequent Events (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended	1 Months Ended		1 Months Ended
	Mar. 31, 2014 property	Dec. 31, 2013 property	May 08, 2014 Subsequent Event [Member] lease	Mar. 31, 2014 Property Subject to Ground Lease [Member]	May 08, 2014 Property Subject to Ground Lease [Member] Subsequent Event [Member] property
Subsequent Event [Line Items]
Number of ground leases			1
Number of operating properties sold	11	20			3
Total assets	$ 3,869,172	$ 4,223,929		$ 10,900