Income Taxes (Tax Treatment of Distributions and Consolidated Benefit for Income Taxes) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Tax treatment of distributions:
Ordinary income (in dollars per share)	$ 3.02368	$ 2.61271	$ 2.65787
Qualified ordinary income (in dollars per share)	0.01632	0.10474	0.03718
Long-term capital gain (in dollars per share)	0.00000	0.16224	0.03995
Unrecaptured Section 1250 gain (in dollars per share)	0.00000	0.08531	0.00000
Distribution reported for 1099-DIV purposes (in dollars per share)	$ 3.04000	$ 2.96500	$ 2.73500
REIT distribution requirement (as a percent)	90.00%	90.00%	90.00%
Provision (benefit) for income taxes
Current - Federal	$ 138	$ 878	$ 3,145
Current - State	1,453	0	(461)
Deferred - Federal	(25,962)	(3,338)	(11,860)
Deferred - State	(3,054)	(1,772)	(2,396)
Current - Foreign	953	327	0
Deferred - Foreign	(12,812)	(4,827)	(256)
Income tax expense (benefit)	$ (39,284)	$ (8,732)	$ (11,828)