Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
REVENUES:
Contract drilling	$ 282,546	$ 338,621	$ 577,161	$ 675,382
Revenues related to reimbursable expenses	13,805	11,766	27,009	26,731
Total revenues	296,351	350,387	604,170	702,113
COSTS AND EXPENSES:
Contract drilling	89,918	131,124	220,570	267,589
Reimbursable expenses	9,123	8,661	17,409	20,568
Depreciation	41,053	42,528	83,880	87,103
General and administrative	11,488	14,737	26,665	32,146
Asset impairment	708	0	65,432	60,777
Loss on sale of assets	77	5,529	77	15,335
Other, net	(1,137)	0	(1,060)	0
Total costs and expenses	151,230	202,579	412,973	483,518
OPERATING INCOME	145,121	147,808	191,197	218,595
OTHER INCOME (EXPENSE):
Interest expense, net of capitalized interest	(17,098)	(12,847)	(30,859)	(28,351)
Interest income	6	15	10	72
Gains on extinguishment of debt	8,397	0	8,397	0
Other income	0	0	17,976	0
Other income (expense) total	(8,695)	(12,832)	(4,476)	(28,279)
INCOME BEFORE INCOME TAXES	136,426	134,976	186,721	190,316
PROVISION FOR INCOME TAXES	13,989	12,307	25,203	21,429
NET INCOME	$ 122,437	$ 122,669	$ 161,518	$ 168,887
EARNINGS PER COMMON SHARE:
Basic (in dollars per share)	$ 1.89	$ 1.90	$ 2.49	$ 2.62
Diluted (in dollars per share)	$ 1.89	$ 1.89	$ 2.49	$ 2.60
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic (in shares)	64,781	64,620	64,739	64,513
Diluted (in shares)	64,825	65,048	64,870	65,031