Incentive Plan (Summary of Stock Options Outstanding and Exercisable) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Exercise price range, lower ($ per share)	$ 41.73
Exercise price range, upper ($ per share)	$ 41.73
Number outstanding (shares)	20,677	51,622
Weighted-average remaining contractual life (years)	10 months 2 days
Weighted average exercise price, outstanding ($ per share)	$ 41.73
Aggregate intrinsic value	$ 1,390,735