Stockholders' Equity (Changes in Nonvested Stock Options) (Details) - $ / shares shares in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Stock-Based Compensation
Number of Options, beginning balance	2,076	2,075
Weighted-Average Grant Date Fair Value Per Share, beginning balance	$ 18.58	$ 14.90
Options granted, Number of options	0	780
Options granted, Weighted-Average Grant Date Fair Value Per Share	$ 0.00	$ 25.05
Options vested, Number of options	(1)	(762)
Options vested, Weighted-Average Grant Date Fair Value Per Share	$ 16.62	$ 15.26
Options forfeited, Number of options	(11)	(29)
Options forfeited, Weighted-Average Grant Date Fair Value Per Share	$ 15.74	$ 14.99
Number of Options, ending balance	2,064	2,064
Weighted-Average Grant Date Fair Value Per Share, ending balance	$ 18.60	$ 18.60