SUPPLEMENTAL BALANCE SHEET INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Reserve for bad debt:
Balance at the beginning of the period	$ 4,795	$ 942	$ 776
Provision for (recovery of) bad debt	(200)	3,875	205
Write-off of bad debt	2	(22)	(39)
Balance at the end of the period	4,597	4,795	942
Prepaid expenses and other current assets:
Restricted cash	28,244	23,691
Prepaid insurance	13,316	14,250
Deferred mobilization	20,133	11,395
Income tax asset		9,322
Prepaid value added tax	434	5,004
Other	19,150	16,276
Total prepaid expenses and other current assets	81,277	79,938
Accrued liabilities:
Accrued operating costs	91,408	30,169
Payroll and employee benefits	88,128	71,658
Taxes payable, other than income tax	42,538	38,328
Accrued income taxes	10,611
Deferred mobilization	18,103	12,235
Self-insurance liabilities	8,118	7,028
Deferred income	3,144	11,663
Other	20,228	18,603
Total accrued liabilities	282,278	189,684
Noncurrent liabilities - Other:
Pension and other non-qualified retirement plans	25,305	23,404
Self-insurance liabilities	13,476	12,207
Deferred mobilization	3,818	8,067
Deferred income		1,781
Uncertain tax positions including interest and penalties	13,239	12,844
Other	8,272	7,048
Total noncurrent liabilities - other	$ 64,110	$ 65,351