Stockholders Equity - Common Stock Dividends (Details) - $ / shares													3 Months Ended
	Apr. 30, 2020	Mar. 11, 2020	Jan. 31, 2020	Dec. 11, 2019	Oct. 31, 2019	Sep. 10, 2019	Jul. 31, 2019	Jun. 11, 2019	Apr. 30, 2019	Mar. 12, 2019	Jan. 31, 2019	Dec. 12, 2018	Mar. 31, 2020	Mar. 31, 2019
Dividends
Dividend per Share, declared		$ 0.40		$ 0.40		$ 0.40		$ 0.40		$ 0.40		$ 0.40	$ 0.40	$ 0.40
Dividend per Share, paid	$ 0.40		$ 0.40		$ 0.40		$ 0.40		$ 0.40		$ 0.40