Equity Investees (Schedule of Operations For Equity Investees) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]
Revenues	$ 193,038	$ 189,941	$ 246,265
Operating Income	122,836	12,191	146,760
Net Income	$ 118,175	$ 7,810	$ 142,754