Income Taxes (Schedule of Reconciliation of Income Tax Provision (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax	$ 9,151	$ 38,359	$ 29,563
REIT income not subject to federal income tax	(14,110)	(16,812)	(13,918)
Change in valuation allowance	488	(1,818)	(683)
State income taxes, net of federal income tax	(838)	2,234	942
Domestic production activities deduction	0	(1,055)	(1,579)
Permanent Book-Tax Differences	(70)	(1,073)	(384)
All other items	(189)	(148)	(56)
Income tax (benefit) provision	$ (5,568)	$ 19,687	$ 13,885
Effective tax rate	(21.30%)	18.00%	16.40%