CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Balance, Beginning of period at Sep. 30, 2013	$ 1,937,635	$ 132,573	$ 1,625,051	$ 594,450	$ 6,378	$ (420,817)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,236			40,236
Other comprehensive income adjustment	(6,183)				(6,183)
Dividends paid on common stock	(10,179)			(10,179)
Compensation expense related to common stock options	300		300
Proceeds from exercise of common stock options	9,280	700	8,580
Restricted stock	840		840
Treasury stock acquired	(18,945)					(18,945)
Balance, End of period at Dec. 31, 2013	$ 1,952,984	$ 133,273	$ 1,634,771	$ 624,507	$ 195	$ (439,762)