Income Taxes Text Details Income Tax Components (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Expense Components [Line Items]
Statutory Federal income tax rate		21.00%	35.00%	35.00%
Other information pertaining to income taxes	On December 22, 2017, H.R. 1, the Tax Act, was enacted by the U.S. government. Substantially all of the provisions of the Tax Act were effective as of January 1, 2018. The Tax Act includes significant changes to the Internal Revenue Code of 1986, as amended, including amendments which significantly change the taxation of business entities. The more significant changes in the Tax Act that impact the Company are the reduction in the federal corporate tax rate from 35% to 21% and the changes to the deductibility of executive compensation. Under ASC 740, the tax effects of changes in tax laws must be recognized in the period in which the law is enacted, or the fourth quarter of 2017 for the Tax Act. ASC 740 also requires deferred tax assets and liabilities to be measured at the enacted tax rate expected to apply when temporary differences are to be realized or settled. In the fourth quarter of 2017, the Company re-measured its deferred tax assets and liabilities at the 21% federal corporate tax rate, reevaluated its investments in affordable housing projects using the 21% federal corporate tax rate, and reduced its deferred tax assets associated with executive compensation that is no longer deductible.
Change in enacted tax rate	$ 12,900
Increase (decrease) in deferred income taxes		$ (2,400)
Deferred income tax expense/ (benefit)		5,220	$ 22,511	$ 2,948
Unrecognized tax benefits that would impact effective tax rate	900	800	900	800
Income tax penalties and interest expense		0	0	0
Income tax penalties and interest accrued	$ 0	0	$ 0	$ 0
Shareholders' Equity
Income Tax Expense Components [Line Items]
Deferred income tax expense/ (benefit)		3,700
Income Tax Expense Components, Continuing Operations
Income Tax Expense Components [Line Items]
Deferred income tax expense/ (benefit)		5,200
Discontinued Operations
Income Tax Expense Components [Line Items]
Deferred income tax expense/ (benefit)		$ 700