|
Senior Unsecured Notes (Summary Of Senior Unsecured Notes) (Details) (USD $)
In Thousands, unless otherwise specified
|
3 Months Ended |
|
|
Mar. 31, 2015
|
Dec. 31, 2014
|
| Debt Instrument [Line Items] |
|
|
|
| Senior Unsecured Notes |
$ 1,268,018 |
|
$ 1,267,744 |
| 5.800% Senior Unsecured Notes, Due January 15, 2016 [Member] |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Senior Unsecured Notes |
200,066 |
|
200,086 |
| Effective Rate |
5.806% |
[1] |
|
| Interest rate of senior unsecured notes |
5.80% |
|
|
| Maturity date of the senior unsecured notes |
Jan. 15, 2016 |
|
|
| 2.500% Senior Unsecured Notes Due December 15, 2017 [Member] |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Senior Unsecured Notes |
249,224 |
|
249,150 |
| Effective Rate |
2.803% |
[1] |
|
| Interest rate of senior unsecured notes |
2.50% |
|
|
| Maturity date of the senior unsecured notes |
Dec. 15, 2017 |
|
|
| 7.750% Senior Unsecured Notes, Due August 15, 2019 [Member] |
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|
|
| Debt Instrument [Line Items] |
|
|
|
| Senior Unsecured Notes |
249,066 |
|
249,013 |
| Effective Rate |
8.017% |
[1] |
|
| Interest rate of senior unsecured notes |
7.75% |
|
|
| Maturity date of the senior unsecured notes |
Aug. 15, 2019 |
|
|
| 4.500% Senior Unsecured Notes Due April 18, 2022 [Member] |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Senior Unsecured Notes |
299,580 |
|
299,565 |
| Effective Rate |
4.612% |
[1] |
|
| Interest rate of senior unsecured notes |
4.50% |
|
|
| Maturity date of the senior unsecured notes |
Apr. 18, 2022 |
|
|
| 3.150% Senior Unsecured Note, Due May 15, 2023 [Member] |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Senior Unsecured Notes |
$ 270,082 |
|
$ 269,930 |
| Effective Rate |
3.517% |
[1] |
|
| Interest rate of senior unsecured notes |
3.15% |
|
|
| Maturity date of the senior unsecured notes |
May 15, 2023 |
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