Income Taxes (Income Tax Benefit (Expense) Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Federal expense at statutory tax rate	$ (54,818)	$ (45,942)	$ (31,723)
Nontaxable income of NNN	53,178	44,746	30,380
State taxes, net of federal benefit	(200)	(139)	(156)
Amortization of Built-in Gain Tax	761	613	531
Other	(6)	(58)	(9)
Valuation allowance (increase) decrease	0	7,671	0
Total benefit (expense) for income taxes	$ (1,085)	$ 6,891	$ (977)