Bank segment (HEI only) Investment Securities (Details) $ in Thousands		12 Months Ended
	Jun. 01, 2015 bank	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Amortized Cost
Due in one year or less		$ 0
Due after one year through five years		86,379
Due after five years through ten years		71,972
Due after ten years		54,883
Total amortized cost		213,234
Mortgage-related securities-FNMA, FHLMC and GNMA - amortized cost		610,522
Total available-for-sale securities, amortized cost		823,756	$ 549,627
Fair value
Due in one year or less		0
Due after one year through five years		86,935
Due after five years through ten years		71,812
Due after ten years		54,212
Total fair value		212,959
Mortgage-related securities-FNMA, FHLMC and GNMA - fair value		607,689
Estimated fair value		820,648	550,394
Gains (losses) from sales of available-for-sale investments
Proceeds		0	79,564	$ 71,367
Available-for-sale securities pledged at carrying value		100,500	88,600
Available-for-sale securities, pledged at carrying value as collateral for securities sold under agreements to repurchase		260,500	230,200
Interest income from taxable and non-taxable investment securities
Taxable		15,120	11,666	11,474
Non-taxable		0	279	1,621
Total		15,120	11,945	13,095
Number of banks merging | bank	2
Redemption of stock from Federal Home Loan Bank		60,223	23,244	3,476
Mortgage-related securities - FNMA, FHLMC and GNMA
Gains (losses) from sales of available-for-sale investments
Proceeds		0	79,600	71,400
Gross gains		0	2,800	1,000
Gross losses		0	0	$ 0
U.S. Treasury and federal agency obligations
Amortized Cost
Total available-for-sale securities, amortized cost			119,507
Fair value
Estimated fair value			119,560
FHLB Seattle
Interest income from taxable and non-taxable investment securities
Cost method investments		10,700	69,300
Excess FHLB stock in excess of requirement			55,000
Redemption of stock from Federal Home Loan Bank		$ 58,600	$ 23,200