Income Taxes Operating loss carryforwards (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 845,703
Tax Year 2007 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	53,909
Tax Year 2008 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	53,696
Tax Year 2009 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	506,552
Tax Year 2010 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	85,215
Tax Year 2011 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	42,189
Tax Year 2012 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	32,152
Tax Year 2013 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	29,913
Tax Year 2014 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	6,932
Tax Year 2016 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	15,517
Tax Year 2017 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 19,628