Income Taxes (Narrative) (Details) - USD ($) $ in Thousands			12 Months Ended
	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Net tax credits			$ 4,800	$ 1,200	$ 1,600
Operating loss carryforwards			$ 25,100
Tax Cuts and Jobs Act, Measurement Period Adjustment, Income Tax Expense (Benefit)					47,500
Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense					31,500
Tax Cuts and Jobs Act, Change in Tax Rate, Income Tax Expense (Benefit)					$ (28,700)
Tax Cuts and Jobs Act, Incomplete Accounting, Provisional Cumulative Temporary Difference				$ 10,400
Income tax expense at federal statutory rate			21.00%	21.00%	35.00%
Increase (decrease) in deferred income taxes			$ (34,500)
Deferred tax expense (benefit)			927	$ 9,472	$ (9,074)
Tax benefit directly allocated to shareholder's equity			33,600
Valuation allowance			38,181	38,181
Net operating loss and credit carry forwards			69,827	70,808
Unrecognized deferred tax liability for thrift bad-debt reserves			15,300
Unrecognized tax benefits that would impact effective tax rate			3,900	2,300	2,800
Interest and penalties			100	0	200
Accrued interest and penalties related to UTBs			1,800	$ 1,800
Cumulative taxable temporary differences			58,000
Research Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Net tax credits			3,000
Investment Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Net tax credits			2,400
General Business Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Net tax credits			700
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance			38,200
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration			644,400
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax Cuts and Jobs Act, Measurement Period Adjustment, Income Tax Expense (Benefit)					37,500
Tax Cuts and Jobs Act, Decrease in Deferred Tax Liability due to Transition Tax					1,800
Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense					39,300
Deferred Tax Assets, Operating Loss Carryforwards, Domestic			$ 1,200,000
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax Cuts and Jobs Act, Measurement Period Adjustment, Income Tax Expense (Benefit)					10,000
Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense					10,600
Tax Cuts and Jobs Act, Change in Tax Rate, Income Tax Expense (Benefit)					$ 20,900
Minimum [Member] | Forecast [Member]
Operating Loss Carryforwards [Line Items]
Decrease in UTBs		$ (1,900)
Maximum [Member] | Forecast [Member]
Operating Loss Carryforwards [Line Items]
Decrease in UTBs	$ (2,700)