Income Taxes Charaterization of Distributions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Dividends per common share:	$ 2.96	$ 2.80	$ 2.66
Percent of Total Dividends Paid	100.00%	100.00%	100.00%
Ordinary Income [Member]
Income Tax Contingency [Line Items]
Dividends per common share:	$ 1.66	$ 1.58	$ 0.83
Percent of Total Dividends Paid	56.00%	56.40%	31.20%
Capital Gains [Member]
Income Tax Contingency [Line Items]
Dividends per common share:	$ 0	$ 0.13	$ 0
Percent of Total Dividends Paid	0.00%	4.80%	0.00%
Return of Capital [Member]
Income Tax Contingency [Line Items]
Dividends per common share:	$ 1.30	$ 1.09	$ 1.83
Percent of Total Dividends Paid	44.00%	38.80%	68.80%