Income Taxes (Federal Statutory Income Tax Rate To Income Before Income Taxes) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income from continuing operations before income taxes	$ 114,424,000	$ 425,572,000	$ 109,047,000
Partnership income not subject to tax	(109,111,000)	(418,500,000)	(104,751,000)
Income subject to income taxes	5,313,000	7,072,000	4,296,000
Tax expense at federal statutory rate	1,860,000	2,475,000	1,504,000
State income taxes, net of federal tax	949,000	928,000	992,000
Return to provision, federal and state	(198,000)	(193,000)	(232,000)
Other	731,000	777,000	581,000
Income tax expense	$ 3,342,000	$ 3,987,000	$ 2,845,000
Effective tax rate on income from continuing operations before income taxes	3.00%	1.00%	3.00%
Liability for uncertain tax positions	$ 0	$ 0	$ 0