Stockholders' Equity (Narratives) (Details) - $ / shares	3 Months Ended
	Dec. 31, 2017	Sep. 30, 2017
Stockholders' Equity [Abstract]
Dividends payable, date declared	Dec. 06, 2017	Jul. 05, 2017
Declared cash dividend, paid	$ 0.50	$ 1.00
Dividends payable, date of record	Dec. 21, 2017	Jul. 20, 2017
Declared dividend, date paid	Jan. 05, 2018	Aug. 03, 2017