Income Taxes - Effective tax rate based upon total income tax provision (benefit) from continuing operations (Details 1)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	34.00%
Business credits	(0.60%)	(4.80%)
ESOP dividend	(0.40%)	(1.40%)
Stock compensation	(0.40%)	(1.90%)
Domestic production activities deduction	(0.40%)	(2.40%)
Revaluation of deferred taxes for federal tax rate change	0.00%	12.60%
Foreign-derived intangible income deduction	(1.80%)	0.00%
Other	0.00%	0.40%
Effective tax rate	17.40%	36.50%