Consolidated Balance Sheets (Parenthetical) - HECO (USD $)	Jun. 30, 2013	Dec. 31, 2012
Common stock, authorized shares	200,000,000	200,000,000
Common stock, outstanding shares	99,044,053	97,928,403
Hawaiian Electric Company, Inc. and Subsidiaries
Common stock, par value (in dollars per share)	$ 6.67	$ 6.67
Common stock, authorized shares	50,000,000	50,000,000
Common stock, outstanding shares	14,665,264	14,665,264