Stockholders' Equity (Dividends Declared and Paid) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Equity
Dividends declared and paid									$ 24,646	$ 21,263	$ 21,866
Cash dividends per share	$ 0.10	$ 0.10	$ 0.10	$ 0.08	$ 0.08	$ 0.08	$ 0.08	$ 0.08	$ 0.38	$ 0.32	$ 0.32