Real Estate Investments (Impairment of Real Estate Investments) (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charges	$ 91,755	$ 100,547
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of real estate assets deemed to be impaired	340,000	199,500
Estimated fair value of real estate assets deemed to be impaired	$ 248,300	$ 99,000