Financing Agreements Redemption Price Expressed as Percentage of Principal Amount Senior Notes Sold in 2013 (Detail)	0 Months Ended
	Dec. 31, 2014
Senior Notes Due September 2021 [Member] | Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	104.031%
Senior Notes Due September 2021 [Member] | Debt Instrument, Redemption, Period Three [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	102.688%
Senior Notes Due September 2021 [Member] | Debt Instrument, Redemption, Period Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	101.344%
Senior Notes Due September 2021 [Member] | Debt Instrument, Redemption, Period Five [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Senior Notes Due September 2021 [Member] | Debt Instrument Redemption Period Six [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Senior Notes Due September 2023 [Member] | Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	103.00%
Senior Notes Due September 2023 [Member] | Debt Instrument, Redemption, Period Three [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	102.00%
Senior Notes Due September 2023 [Member] | Debt Instrument, Redemption, Period Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	101.00%
Senior Notes Due September 2023 [Member] | Debt Instrument, Redemption, Period Five [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Senior Notes Due September 2023 [Member] | Debt Instrument Redemption Period Six [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%