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