Stockholders' Equity (Narratives) (Details) - $ / shares	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Dividends Declared
Dividends payable, date declared	Mar. 06, 2019
Dividend paid, amount per share	$ 0.5
Dividends payable, date of record	Mar. 21, 2019
Dividends payable, date to be paid	Apr. 04, 2019
Dividends declared two [Member]
Dividends Declared
Dividends payable, date declared	Dec. 05, 2018
Dividend paid, amount per share	$ 0.5
Dividends payable, date of record	Dec. 20, 2018
Dividends payable, date to be paid	Jan. 07, 2019
Dividends declared three [Member]
Dividends Declared
Dividends payable, date declared	Aug. 23, 2018
Dividend paid, amount per share	$ 0.5
Dividends payable, date of record	Sep. 10, 2018
Dividends payable, date to be paid	Sep. 24, 2018
Dividends declared four [Member]
Dividends Declared
Dividends payable, date declared	Jun. 06, 2018
Dividend paid, amount per share	$ 0.5
Dividends payable, date of record	Jun. 21, 2018
Dividends payable, date to be paid	Jul. 05, 2018
Dividends declared five [Member]
Dividends Declared
Dividends payable, date declared	Mar. 08, 2018
Dividend paid, amount per share	$ 0.5
Dividends payable, date of record	Mar. 23, 2018
Dividends payable, date to be paid	Apr. 06, 2018
Dividends declared six [Member]
Dividends Declared
Dividends payable, date declared		Dec. 06, 2017
Dividend paid, amount per share		$ 0.5
Dividends payable, date of record		Dec. 21, 2017
Dividends payable, date to be paid		Jan. 05, 2018
Dividends declared seven [Member]
Dividends Declared
Dividends payable, date declared		Jul. 05, 2017
Dividend paid, amount per share		$ 1
Dividends payable, date of record		Jul. 20, 2017
Dividends payable, date to be paid		Aug. 03, 2017