CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Held-to-maturity debt securities, fair value (in dollars)	$ 63,515	$ 65,133
Preferred stock, no par value	$ 0	$ 0
Class A Common Stock
Common Stock, no par value	0	0
Class B Common Stock
Common Stock, no par value	$ 0	$ 0