Stock-Based Compensation (Changes in Nonvested Stock Options) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
	Mar. 31, 2015	Mar. 31, 2015
Stock-Based Compensation
Number of Options, beginning balance	1,770	1,679
Weighted-Average Exercise Price Per Share, beginning balance	$ 40.48	$ 34.83
Options granted, Number of options	0	751
Options granted, Weighted-Average Exercise Price Per Share		$ 45.55
Options vested, Number of options	(7)	(651)
Options vested, Weighted-Average Exercise Price Per Share	$ 40.72	$ 33.05
Options forfeited, Number of options	(16)	(32)
Options forfeited, Weighted-Average Exercise Price Per Share	$ 38.75	$ 37.09
Number of Options, ending balance	1,747	1,747
Weighted-Average Exercise Price Per Share, ending balance	$ 40.50	$ 40.50