Income Taxes - Tax Status of Dividends (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Document Fiscal Year Focus	2013
Dividend per share	$ 1.85	$ 1.85	$ 1.85
Ordinary income	70.00%	71.00%	33.00%
Capital gain	6.00%	1.00%	1.00%
Return of capital	0.00%	28.00%	66.00%
Allocation of Dividends, Qualified Dividend Income	24.00%	0.00%	0.00%