Investments - Madison (Details) - Madison Paper Industries - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Schedule of Equity Method Investments [Line Items]
Revenues		$ 15,371		$ 40,550
Costs and expenses:
Cost of sales		(17,654)		(66,589)
General and administrative		(2,416)		(65,517)
Operating Expenses		(20,070)		(132,106)
Operating loss		(4,699)		(91,556)
Other (expense)/income		1		2
Net loss		$ (4,698)		$ (91,554)
Subsequent Event
Schedule of Equity Method Investments [Line Items]
Revenues	$ 0		$ 0
Costs and expenses:
Cost of sales	(118)		(1,172)
General and administrative	(528)		(554)
Operating Expenses	(646)		(1,726)
Operating loss	(646)		(1,726)
Other (expense)/income	(4)		(6)
Net loss	$ (650)		$ (1,732)