Stockholders' Equity (Activity for Stock Option Awards) (Details) shares in Thousands	12 Months Ended
	Sep. 30, 2018 $ / shares shares
Stock-Based Compensation
Number of options, beginning balance | shares	5,236
Weighted Average Exercise Price Per Share, beginning balance | $ / shares	$ 39.58
Options granted, Number of options | shares	750
Options granted, Weighted Average Exercise Price Per Share | $ / shares	$ 78.91
Options exercised, Number of options | shares	(334)
Options exercised, Weighted Average Exercise Price Per Share | $ / shares	$ 27.34
Options forfeited, Number of options | shares	(41)
Options forfeited, Weighted Average Exercise Price Per Share | $ / shares	$ 59.64
Number of options, ending balance | shares	5,611
Weighted Average Exercise Price Per Share, ending balance | $ / shares	$ 45.42