Disclosure Of Fair Value Of Assets And Liabilities (Details) - USD ($) |
Jun. 30, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Disclosure Of Fair Value Of Assets And Liabilities [Abstract] | ||
| Fair value of Company's long-term debt | $ 2,302,856,000 | $ 2,150,507,000 |
| Principal balance outstanding | $ 2,256,955,000 | $ 2,145,393,000 |