Stockholders' Equity and Earnings Per Share (Warrants) (Details) - shares	Mar. 31, 2018	Jan. 17, 2014	Jan. 16, 2014
Class of Stock [Line Items]
Number of warrants exercised (in warrants)	0
Common Stock
Class of Stock [Line Items]
Shares of East West's common stock into which the warrant may be converted (in shares)		230,282
MetroCorp | MetroCorp
Class of Stock [Line Items]
Shares of East West's common stock into which the warrant may be converted (in shares)			771,429