Earnings Per Share (Details)	3 Months Ended		12 Months Ended
	Sep. 30, 2017 $ / shares	Sep. 30, 2016 $ / shares	Sep. 30, 2017 Quarter $ / shares	Sep. 30, 2016 Quarter $ / shares	Sep. 30, 2015 $ / shares
Earnings Per Share [Abstract]
Cash dividends common, per share | $ / shares	$ 0.25	$ 0.29	$ 1.00	$ 1.16	$ 1.04
Number of quarterly dividends declared | Quarter			4	4