Bank segment (HEI only) - Available For Sale Investment Securities (Details) $ in Thousands	Dec. 31, 2016 USD ($) issue	Dec. 31, 2015 USD ($) issue
Available-for-sale securities
Total available-for-sale securities, amortized cost	$ 1,118,350	$ 823,756
Gross unrealized gains	2,662	4,589
Gross unrealized losses	(15,830)	(7,697)
Available-for-sale investment securities	$ 1,105,182	$ 820,648
Available-for-sale Securities, Continuous Unrealized Loss Position
Number of issues, less than 12 months | issue	106	51
Fair value, less than 12 months	$ 833,130	$ 388,838
Gross unrealized losses, less than 12 months	$ (14,153)	$ (3,732)
Number of issues, more than 12 months | issue	14	28
Fair value, 12 months or longer	$ 50,970	$ 143,195
Gross unrealized losses, 12 months or longer	(1,677)	(3,965)
U.S. Treasury and federal agency obligations
Available-for-sale securities
Total available-for-sale securities, amortized cost	193,515	213,234
Gross unrealized gains	920	1,025
Gross unrealized losses	(2,154)	(1,300)
Available-for-sale investment securities	$ 192,281	$ 212,959
Available-for-sale Securities, Continuous Unrealized Loss Position
Number of issues, less than 12 months | issue	18	13
Fair value, less than 12 months	$ 123,475	$ 83,053
Gross unrealized losses, less than 12 months	$ (2,010)	$ (866)
Number of issues, more than 12 months | issue	1	3
Fair value, 12 months or longer	$ 3,485	$ 17,378
Gross unrealized losses, 12 months or longer	(144)	(434)
Mortgage-related securities-FNMA, FHLMC and GNMA
Available-for-sale securities
Total available-for-sale securities, amortized cost	909,408	610,522
Gross unrealized gains	1,742	3,564
Gross unrealized losses	(13,676)	(6,397)
Available-for-sale investment securities	$ 897,474	$ 607,689
Available-for-sale Securities, Continuous Unrealized Loss Position
Number of issues, less than 12 months | issue	88	38
Fair value, less than 12 months	$ 709,655	$ 305,785
Gross unrealized losses, less than 12 months	$ (12,143)	$ (2,866)
Number of issues, more than 12 months | issue	13	25
Fair value, 12 months or longer	$ 47,485	$ 125,817
Gross unrealized losses, 12 months or longer	(1,533)	$ (3,531)
Mortgage revenue bond
Available-for-sale securities
Total available-for-sale securities, amortized cost	15,427
Gross unrealized gains	0
Gross unrealized losses	0
Available-for-sale investment securities	$ 15,427
Available-for-sale Securities, Continuous Unrealized Loss Position
Number of issues, less than 12 months | issue	0
Fair value, less than 12 months	$ 0
Gross unrealized losses, less than 12 months	$ 0
Number of issues, more than 12 months | issue	0
Fair value, 12 months or longer	$ 0
Gross unrealized losses, 12 months or longer	$ 0