CONSOLIDATED CONDENSED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Operating revenues:
Drilling - U.S. Land	$ 696,030	$ 617,779
Drilling - Offshore	57,718	50,792
Drilling - International Land	87,267	60,735
Other	3,557	3,282
Total operating revenues	844,572	732,588
Operating costs and other:
Operating costs, excluding depreciation	466,871	391,032
Depreciation	106,599	86,288
General and administrative	32,421	26,163
Research and development	3,353	3,249
Income from asset sales	(5,219)	(4,683)
Total operating costs and expenses	604,025	502,049
Operating income from continuing operations	240,547	230,539
Other income (expense):
Interest and dividend income	426	336
Interest expense	(1,308)	(2,461)
Gain on sale of investment securities	8,752
Other	(2,084)	21
Total other income (expense)	5,786	(2,104)
Income from continuing operations before income taxes	246,333	228,435
Income tax provision	86,722	84,138
Income from continuing operations	159,611	144,297
Loss from discontinued operations before income taxes	(8)	(11)
Loss from discontinued operations	(8)	(11)
NET INCOME	$ 159,603	$ 144,286
Basic earnings per common share:
Income from continuing operations (in dollars per share)	$ 1.50	$ 1.34
Net income (in dollars per share)	$ 1.50	$ 1.34
Diluted earnings per common share:
Income from continuing operations (in dollars per share)	$ 1.48	$ 1.32
Net income (in dollars per share)	$ 1.48	$ 1.32
Weighted average shares outstanding:
Basic (in shares)	105,867	107,186
Diluted (in shares)	107,412	108,788
Dividends declared per common share (in dollars per share)	$ 0.15	$ 0.07