Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) - HECO - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Common stock, authorized shares (in shares)	200,000,000	200,000,000
Common stock, outstanding shares (in shares)	108,745,265	108,583,413
Hawaiian Electric Company, Inc. and Subsidiaries
Nonutility property, plant and equipment, accumulated depreciation	$ 1,232	$ 1,232
Common stock, par value (in dollars per share)	$ 6.67	$ 6.67
Common stock, authorized shares (in shares)	50,000,000	50,000,000
Common stock, outstanding shares (in shares)	16,019,785	16,019,785