Variable Interest Entities Amortization Expense and Tax Credits and Other Tax Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Investments in Qualified Affordable Housing Projects
Amortization expense	$ 1,478	$ 1,030	$ 2,895	$ 1,921
Tax credits and other tax benefits recognized	$ 2,009	$ 1,423	$ 3,967	$ 2,663