Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Available for sale, amortized cost	$ 1,231,568	$ 1,257,830
Ordinary shares, par value	$ 0.0001	$ 0.0001
Ordinary shares, shares authorized	900,000,000	900,000,000
Ordinary Shares A
Ordinary shares, shares issued	10,282,277	10,171,954
Ordinary shares, shares outstanding	10,167,056	10,095,312
Treasury shares, shares	115,221	76,642
Ordinary Shares B
Ordinary shares, shares issued	4,133,366	4,133,366
Ordinary shares, shares outstanding	4,133,366	4,133,366