Incentive Plan (Summary Of Stock Options) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Incentive Plan [Abstract]
Outstanding, beginning of period, Number of Options Granted	280,000
Options granted, Number of Options Granted	0	0	0
Options exercised, Number of Options Granted	(103,750)
Options expired, Number of Options Granted	(1,250)
Outstanding, end of period, Number of Options Granted	175,000	280,000
Exercisable, end of period, Number of Options Granted	175,000
Vested or expected to vest, end of period, Number of Options Granted	175,000
Outstanding, beginning of period, Weighted Average Exercise Price	$ 19.05
Options exercised, Weighted Average Exercise Price	6.98
Options expired, Weighted Average Exercise Price	6.98
Outstanding, end of period, Weighted Average Exercise Price	26.29	$ 19.05
Exercisable, end of period, Weighted Average Exercise Price	26.29
Vested or expected to vest, end of period, Weighted Average Exercise Price	$ 26.29
Outstanding, end of period, Weighted Average Remaining Contractual Term (Years)	3 months 29 days
Exercisable, end of period, Weighted Average Remaining Contractual Term (Years)	3 months 29 days
Vested or expected to vest, end of period, Weighted Average Remaining Contractual Term (Years)	3 months 29 days