Income Taxes (Summary Of Net Operating Loss Carryforwards) (Details) $ in Thousands	Dec. 31, 2016 USD ($)
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 123,304
2017 - 2021
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	28,116
2022 - 2026
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	7,450
2027 - 2031
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	1,199
2032 - 2036
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	9,407
Unlimited
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 77,132