Annual report pursuant to Section 13 and 15(d)

ACCUMULATED OTHER COMPREHENSIVE INCOME - Reclassifications out of AOCI (Details)

v3.10.0.1
ACCUMULATED OTHER COMPREHENSIVE INCOME - Reclassifications out of AOCI (Details) - USD ($)
$ in Thousands
12 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2016
Derivatives      
Interest expense $ (37,427) $ (26,371) $ (24,344)
Income before income tax 97,993 96,287 95,234
Income tax benefit (provision) 9,118 (22,354) (29,073)
Net income 107,111 73,933 66,161
Prior service (cost) credit      
Postretirement benefit plans      
Income before income tax 333 376 378
Actuarial losses      
Postretirement benefit plans      
Income before income tax (7,018) (10,034) (7,468)
Postretirement Benefit Plans      
Postretirement benefit plans      
Income before income tax (6,685) (9,658) (7,090)
Income taxes (1,638) (3,767) (2,765)
Net income (5,047) (5,891) (4,325)
Derivatives      
Postretirement benefit plans      
Net income 1,042 1,069 (1,919)
Derivatives | Reclassification out of Accumulated Other Comprehensive Income      
Derivatives      
Interest expense 1,380 1,752 (3,146)
Income before income tax 1,380 1,752 (3,146)
Income tax benefit (provision) (338) (683) 1,227
Net income $ 1,042 $ 1,069 $ (1,919)