| **Fair Value Of Financial Instruments (Tables)**                         | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
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| **Fair Value Of Financial Instruments [Abstract]**                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Schedule Of Carrying Amounts And Estimated Fair Values Of Long-Term Debt | ﻿

						 

						 

						 

						 

						 

						 

﻿

						 

						 

						 

						 

						 

						 

﻿

						 

June 30,

						 

December 31,

﻿

						 

2017

						 

2016

﻿Carrying Amount

						 

$
1,987,909 				
						 

$
1,910,633 				
﻿Estimated Fair Value

						 

						 
2,049,090 				
						 

						 
2,018,933 				
﻿ |

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| - Definition
Tabular disclosure of the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.
+ References
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| - References
No definition available.
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