v3.3.1.900
Derivative Financial Instruments and Hedging Activities Fixed-to-Floating Interest Rate Swaps (Details)
$ in Millions
12 Months Ended
Dec. 31, 2015
USD ($)
Derivative [Line Items]  
Notional amount $ 50
Fixed interest rate received 2.52%
Floating interest rate paid 0.00%
Notes due 2017 [Member]  
Derivative [Line Items]  
Notional amount $ 150
Fixed interest rate received 5.30%
Floating interest rate paid 4.59%
Senior notes due 2017 [Member]  
Derivative [Line Items]  
Notional amount $ 750
Fixed interest rate received 1.50%
Floating interest rate paid 0.71%
Notes due 2018 [Member]  
Derivative [Line Items]  
Notional amount $ 415
Fixed interest rate received 5.60%
Floating interest rate paid 3.78%
Notes due 2019 [Member]  
Derivative [Line Items]  
Notional amount $ 300
Fixed interest rate received 6.95%
Floating interest rate paid 5.66%
Debentures due 2019 [Member]  
Derivative [Line Items]  
Notional amount $ 25
Fixed interest rate received 8.875%
Floating interest rate paid 4.59%
Debentures due 2020 [Member]  
Derivative [Line Items]  
Notional amount $ 150
Fixed interest rate received 3.875%
Floating interest rate paid 2.45%
Notes due 2021 [Member]  
Derivative [Line Items]  
Notional amount $ 275
Fixed interest rate received 3.47%
Floating interest rate paid 2.07%
Senior notes due 2022 [Member]  
Derivative [Line Items]  
Notional amount $ 1,350
Fixed interest rate received 2.75%
Floating interest rate paid 0.80%
Notes due 2023 [Member]  
Derivative [Line Items]  
Notional amount $ 200
Fixed interest rate received 3.68%
Floating interest rate paid 1.40%
Debentures due 2024 [Member]  
Derivative [Line Items]  
Notional amount $ 25
Fixed interest rate received 7.625%
Floating interest rate paid 3.01%
Debentures due 2029 [Member]  
Derivative [Line Items]  
Notional amount $ 50
Fixed interest rate received 7.65%
Floating interest rate paid 3.17%
Debentures due 2034 [Member]  
Derivative [Line Items]  
Notional amount $ 25
Fixed interest rate received 5.45%
Floating interest rate paid 0.80%
London Interbank Offered Rate (LIBOR) [Member]  
Derivative [Line Items]  
Debt Instrument, Term 3 months
Derivative, Basis Spread on Variable Rate 0.00%
London Interbank Offered Rate (LIBOR) [Member] | Notes due 2017 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 1 month
Derivative, Basis Spread on Variable Rate 4.26%
London Interbank Offered Rate (LIBOR) [Member] | Senior notes due 2017 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 1 month
Derivative, Basis Spread on Variable Rate 0.46%
London Interbank Offered Rate (LIBOR) [Member] | Notes due 2018 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 6 months
Derivative, Basis Spread on Variable Rate 3.18%
London Interbank Offered Rate (LIBOR) [Member] | Notes due 2019 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 3 months
Derivative, Basis Spread on Variable Rate 5.07%
London Interbank Offered Rate (LIBOR) [Member] | Debentures due 2019 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 6 months
Derivative, Basis Spread on Variable Rate 3.84%
London Interbank Offered Rate (LIBOR) [Member] | Debentures due 2020 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 1 month
Derivative, Basis Spread on Variable Rate 2.12%
London Interbank Offered Rate (LIBOR) [Member] | Notes due 2021 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 1 month
Derivative, Basis Spread on Variable Rate 1.74%
London Interbank Offered Rate (LIBOR) [Member] | Senior notes due 2022 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 1 month
Derivative, Basis Spread on Variable Rate 0.56%
London Interbank Offered Rate (LIBOR) [Member] | Notes due 2023 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 1 month
Derivative, Basis Spread on Variable Rate 1.07%
London Interbank Offered Rate (LIBOR) [Member] | Debentures due 2024 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 6 months
Derivative, Basis Spread on Variable Rate 2.48%
London Interbank Offered Rate (LIBOR) [Member] | Debentures due 2029 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 6 months
Derivative, Basis Spread on Variable Rate 2.57%
London Interbank Offered Rate (LIBOR) [Member] | Debentures due 2034 [Member]  
Derivative [Line Items]  
Debt Instrument, Term 6 months
Derivative, Basis Spread on Variable Rate 0.28%