Basis of Presentation (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Cash and cash equivalents	$ 47,651		$ 69,252	$ 47,651	$ 69,252	$ 58,853	$ 51,433
Deferred income tax provision	7,738		1,662	20,812	4,203
Equity in net income (loss) of affiliates	43,357		25,087	89,851	(51,758)
Net income (loss)	32,552		$ 17,800	$ 63,238	$ (64,842)
Restatement Adjustment [Member] | Overstatement [Member]
Deferred income tax provision		$ 6,900
Equity in net income (loss) of affiliates	5,100
Net income (loss)	$ 3,200