Real Estate and Lease Intangibles - Acquisitions and Dispositions - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Real Estate [Abstract]
Net gain on sales of real estate properties	$ 17,328	$ 90,036	$ 141,761	$ 3,870,871
Net gain (loss) on sales of land parcels		$ 4,037	$ 19,170	$ 15,759