Disclosure Of Fair Value Of Assets And Liabilities (Details) - USD ($) |
Sep. 30, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Disclosure Of Fair Value Of Assets And Liabilities [Abstract] | ||
| Fair value of Company's long-term debt | $ 2,483,897,000 | $ 2,150,507,000 |
| Principal balance outstanding | $ 2,455,309,000 | $ 2,145,393,000 |