Income Tax (Net Operating and Capital Loss Carryforwards for Tax Purposes) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	$ 21
Domestic Tax Authority [Member] | 2015-2019
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	0
Domestic Tax Authority [Member] | 2020-2024
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	0
Domestic Tax Authority [Member] | 2025-2029
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	0
Domestic Tax Authority [Member] | 2030-2034
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	21
Domestic Tax Authority [Member] | Indefinite
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	0
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	137
State and Local Jurisdiction [Member] | 2015-2019
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	32
State and Local Jurisdiction [Member] | 2020-2024
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	44
State and Local Jurisdiction [Member] | 2025-2029
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	53
State and Local Jurisdiction [Member] | 2030-2034
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	8
State and Local Jurisdiction [Member] | Indefinite
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards	$ 0