Long-Term Borrowings - Schedule of percentage of redemption price borrowings (Details)	12 Months Ended
	Sep. 30, 2017
5.5% Senior Notes due June 1, 2024 [Member] | 2019
Senior Notes [Abstract]
Redemption prices percentage	102.75%
5.5% Senior Notes due June 1, 2024 [Member] | 2020
Senior Notes [Abstract]
Redemption prices percentage	101.833%
5.5% Senior Notes due June 1, 2024 [Member] | 2021
Senior Notes [Abstract]
Redemption prices percentage	100.917%
5.5% Senior Notes due June 1, 2024 [Member] | 2022 and thereafter
Senior Notes [Abstract]
Redemption prices percentage	100.00%
5.75% Senior Notes due March 1, 2025 [Member] | 2020
Senior Notes [Abstract]
Redemption prices percentage	102.875%
5.75% Senior Notes due March 1, 2025 [Member] | 2021
Senior Notes [Abstract]
Redemption prices percentage	101.917%
5.75% Senior Notes due March 1, 2025 [Member] | 2022
Senior Notes [Abstract]
Redemption prices percentage	100.958%
5.75% Senior Notes due March 1, 2025 [Member] | 2023 and thereafter
Senior Notes [Abstract]
Redemption prices percentage	100.00%
5.875% Senior Notes due March 1, 2027 [Member] | 2022
Senior Notes [Abstract]
Redemption prices percentage	102.938%
5.875% Senior Notes due March 1, 2027 [Member] | 2023
Senior Notes [Abstract]
Redemption prices percentage	101.958%
5.875% Senior Notes due March 1, 2027 [Member] | 2024
Senior Notes [Abstract]
Redemption prices percentage	100.979%
5.875% Senior Notes due March 1, 2027 [Member] | 2025 and thereafter
Senior Notes [Abstract]
Redemption prices percentage	100.00%