Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2014		Mar. 31, 2013
Net income	$ 52,216		$ 41,679		$ 71,504		$ 51,431
Other comprehensive income:
Unrealized gain on pension plan obligation	528	[1]	664	[1]	1,056	[1]	1,328	[1]
Tax effect of unrealized gain on pension plan	(216)		(271)		(432)		(542)
Total other comprehensive income	312		393		624		786
Total comprehensive income	$ 52,528		$ 42,072		$ 72,128		$ 52,217

[1] These items are included in the computation of net periodic pension cost. See Note 10 - Employee Benefit Plan.