Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ / shares in Thousands, $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Securities available-for-sale, amortized cost	$ 2,157,610	$ 2,087,069
Unearned income on loans	$ (42,373)	$ (59,374)
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	115,000	63,033
Common stock, outstanding	57,724	57,437