Financing Agreements - Redemption Price Expressed as Percentage of Principal Amount (Details) - Senior Notes Due April 2025 [Member]	Sep. 30, 2017
Debt Instrument, Redemption, Period Three [Member]
Debt Instrument [Line Items]
Debt redemption price	104.313%
Debt Instrument, Redemption, Period Four [Member]
Debt Instrument [Line Items]
Debt redemption price	102.875%
Debt Instrument, Redemption, Period Five [Member]
Debt Instrument [Line Items]
Debt redemption price	101.438%
Debt Instrument Redemption Period Six [Member]
Debt Instrument [Line Items]
Debt redemption price	100.00%
Debt Instrument Redemption Period Seven [Member]
Debt Instrument [Line Items]
Debt redemption price	100.00%