Stockholders' Equity Dividends Declared (Details) - $ / shares	Feb. 06, 2019	Oct. 29, 2018	Aug. 08, 2018	May 03, 2018	Feb. 02, 2018
Dividends Declared [Abstract]
Dividend, declaration date	Feb. 06, 2019	Oct. 29, 2018	Aug. 08, 2018	May 03, 2018	Feb. 02, 2018
Dividend amount to be paid, per common share	$ 0.4450	$ 0.4350	$ 0.4250	$ 0.4150	$ 0.4050
Dividend, date of record	Feb. 25, 2019	Nov. 19, 2018	Aug. 20, 2018	May 18, 2018	Feb. 22, 2018
Dividend, date to be paid	Mar. 12, 2019	Dec. 05, 2018	Sep. 04, 2018	Jun. 01, 2018	Mar. 09, 2018