Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
ASSETS
Available-for-sale securities pledged as collateral	$ 448,964	$ 435,833
Allowance for loan losses	317,894	311,322
Loans held-for-investment pledged as collateral	20,952,709	20,590,035
Premises and equipment, accumulated depreciation	$ 122,396	$ 118,547
STOCKHOLDERS’ EQUITY
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	166,484,022	165,867,587
Treasury stock, shares (in shares)	20,982,721	20,906,224