GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION - Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net loss	$ (154,683)	$ (8,008)	$ (74,833)	$ 480,219
Other comprehensive income, net of income taxes:
Unrealized appreciation (depreciation) on securities, net	0	13,826	0	5,657
Minimum pension liability adjustments, net	226	337	675	985
Other comprehensive income	226	14,163	675	6,642
Comprehensive income (loss)	(154,457)	6,155	(74,158)	486,861
Eliminations
CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net loss	148,857	6,976	49,077	(497,765)
Other comprehensive income, net of income taxes:
Unrealized appreciation (depreciation) on securities, net		0		0
Minimum pension liability adjustments, net	0	0	0	0
Other comprehensive income	0	0	0	0
Comprehensive income (loss)	148,857	6,976	49,077	(497,765)
Helmerich & Payne, Inc. (Guarantor) | Reportable Legal Entities
CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net loss	(154,683)	(8,008)	(74,833)	480,219
Other comprehensive income, net of income taxes:
Unrealized appreciation (depreciation) on securities, net		0		0
Minimum pension liability adjustments, net	78	101	233	295
Other comprehensive income	78	101	233	295
Comprehensive income (loss)	(154,605)	(7,907)	(74,600)	480,514
Helmerich & Payne International Drilling Co. (Issuer) | Reportable Legal Entities
CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net loss	(120,513)	(6,482)	(18,185)	494,775
Other comprehensive income, net of income taxes:
Unrealized appreciation (depreciation) on securities, net		13,826		5,657
Minimum pension liability adjustments, net	148	236	442	690
Other comprehensive income	148	14,062	442	6,347
Comprehensive income (loss)	(120,365)	7,580	(17,743)	501,122
Non-Guarantor Subsidiaries | Reportable Legal Entities
CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net loss	(28,344)	(494)	(30,892)	2,990
Other comprehensive income, net of income taxes:
Unrealized appreciation (depreciation) on securities, net		0		0
Minimum pension liability adjustments, net	0	0	0	0
Other comprehensive income	0	0	0	0
Comprehensive income (loss)	$ (28,344)	$ (494)	$ (30,892)	$ 2,990