Income Taxes (Tax Expense and Effective Tax Rate) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Income Taxes
Earnings before income taxes	$ 56,756	$ 50,336	$ 89,700	$ 88,873
Income tax expense	$ 11,958	$ 7,890	$ 21,519	$ 19,059
Effective tax rate	21.10%	15.70%	24.00%	21.40%