Bank segment (HEI only) - Credit Risk Profile by Internally Assigned Grade for Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Credit risk profile by internally assigned grade for loans
Total financing receivables	$ 4,743,619	$ 4,622,068
Loans, Excluding Consumer Loans
Credit risk profile by internally assigned grade for loans
Total financing receivables	1,619,214	1,550,016
Loans, Excluding Consumer Loans | Pass
Credit risk profile by internally assigned grade for loans
Total financing receivables	1,418,751	1,432,609
Loans, Excluding Consumer Loans | Special mention
Credit risk profile by internally assigned grade for loans
Total financing receivables	90,770	28,544
Loans, Excluding Consumer Loans | Substandard
Credit risk profile by internally assigned grade for loans
Total financing receivables	109,693	88,416
Loans, Excluding Consumer Loans | Doubtful
Credit risk profile by internally assigned grade for loans
Total financing receivables	0	447
Loans, Excluding Consumer Loans | Loss
Credit risk profile by internally assigned grade for loans
Total financing receivables	0	0
Commercial real estate
Credit risk profile by internally assigned grade for loans
Total financing receivables	800,395	690,561
Commercial real estate | Pass
Credit risk profile by internally assigned grade for loans
Total financing receivables	701,657	642,410
Commercial real estate | Special mention
Credit risk profile by internally assigned grade for loans
Total financing receivables	65,541	7,710
Commercial real estate | Substandard
Credit risk profile by internally assigned grade for loans
Total financing receivables	33,197	40,441
Commercial real estate | Doubtful
Credit risk profile by internally assigned grade for loans
Total financing receivables	0	0
Commercial real estate | Loss
Credit risk profile by internally assigned grade for loans
Total financing receivables	0	0
Commercial construction
Credit risk profile by internally assigned grade for loans
Total financing receivables	126,768	100,796
Commercial construction | Pass
Credit risk profile by internally assigned grade for loans
Total financing receivables	102,955	86,991
Commercial construction | Special mention
Credit risk profile by internally assigned grade for loans
Total financing receivables	0	13,805
Commercial construction | Substandard
Credit risk profile by internally assigned grade for loans
Total financing receivables	23,813	0
Commercial construction | Doubtful
Credit risk profile by internally assigned grade for loans
Total financing receivables	0	0
Commercial construction | Loss
Credit risk profile by internally assigned grade for loans
Total financing receivables	0	0
Commercial loans
Credit risk profile by internally assigned grade for loans
Total financing receivables	692,051	758,659
Commercial loans | Pass
Credit risk profile by internally assigned grade for loans
Total financing receivables	614,139	703,208
Commercial loans | Special mention
Credit risk profile by internally assigned grade for loans
Total financing receivables	25,229	7,029
Commercial loans | Substandard
Credit risk profile by internally assigned grade for loans
Total financing receivables	52,683	47,975
Commercial loans | Doubtful
Credit risk profile by internally assigned grade for loans
Total financing receivables	0	447
Commercial loans | Loss
Credit risk profile by internally assigned grade for loans
Total financing receivables	$ 0	$ 0