Income Taxes (Schedule of Reconciliation of Income Tax Provision (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax	$ 2,314	$ 9,151	$ 38,359
REIT income not subject to federal income tax	(7,199)	(14,110)	(16,812)
Intercompany profit-in-inventory elimination adjustment	1,465
Change in valuation allowance	162	488	(1,818)
State income taxes, net of federal income tax	(740)	(838)	2,234
Domestic production activities deduction	(2)		(1,055)
Permanent book-tax differences	(218)	(70)	(1,073)
Research and development credits	(689)
All other items	582	(189)	(148)
Income tax (benefit) provision	$ (4,325)	$ (5,568)	$ 19,687
Effective tax rate	(65.40%)	(21.30%)	18.00%