Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Deferred tax asset, net	$ 0	$ 34,322
Valuation allowance	1,090	1,090
Deferred tax assets, gross	93,000	205,800
Unrecognized tax benefits	$ 3,100	3,000
Effective income tax rate on unrecognized tax benefits that would impact effective tax rate	1.00%
Accrued interest related to unrecognized tax benefits	$ 353	354
State and Local Jurisdiction
Income Tax Contingency [Line Items]
Valuation allowance	1,100	1,100
Tax credit carryforward, amount	$ 4,300	5,600
State tax credits benefit period	5 years
State tax credits carry forward period	8 years
Domestic Tax Authority | Low Income Housing Tax Credit And Other Carryforward
Income Tax Contingency [Line Items]
Tax credit carryforward, amount	$ 7,900	5,900
Tax credit carryforward, carryforward term	20 years
Domestic Tax Authority | Alternative Minimum Tax, Tax Credit Carryforward [Member]
Income Tax Contingency [Line Items]
Tax credit carryforward, amount	$ 9,500	$ 9,500