Debt Obligations (4.25% Senior Unsecured Notes) (Details) - USD ($) |
12 Months Ended | ||||||
---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
May. 31, 2014 |
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Debt Instrument [Line Items] | |||||||
Payments Of Debt Extinguishment Costs | $ 11,000,000 | ||||||
Debt issuance cost | $ 16,000,000 | ||||||
Senior Notes [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Debt instrument, interest rate | 4.00% | ||||||
Payments Of Debt Extinguishment Costs | $ 9,000,000 | ||||||
Senior Notes [Member] | 4.25% Senior Unsecured Notes Due June 1 2024 [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Total debt obligations | [1],[2] | $ 495,000,000 | $ 494,000,000 | ||||
Debt instrument, face amount | $ 500,000,000 | ||||||
Debt instrument, interest rate | 4.25% | 4.25% | |||||
Debt instrument, maturity date | Jun. 01, 2024 | ||||||
Maximum interest rate on debt instrument | 6.25% | ||||||
Aggregate principal amount purchased plus accrued and unpaid interest | 101.00% | ||||||
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