Share-based compensation (Details 4) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Weighted-average grant-date fair value per share
Total weighted-average grant-date fair value	$ 100,000		$ 0
Tax benefits	900,000		500,000		2,200,000		1,900,000
Long-term incentive plan (LTIP)
Share-based compensation
Payout low end of range (as a percent)					0.00%	[1]
Payout high end of range (as a percent)					200.00%
LTIP linked to TRS
Share-based compensation
Period for calculating total return to shareholders					3 years
LTIP linked to TRS and other performance conditions (in shares)
Outstanding, beginning of period (in shares)	235,064		239,407		239,256		197,385
Granted (in shares)	1,505		1,723		91,038		80,647
Vested (in shares)					(87,753)		(35,397)
Forfeited (in shares)	(4,442)		(2,450)		(10,414)		(3,955)
Outstanding, end of period (in shares)	232,127		238,680		232,127		238,680
Weighted-average grant-date fair value per share
Outstanding, beginning of period (in dollars per share)	$ 32.87	[1]	$ 29.12	[1]	$ 29.12	[1]	$ 25.94	[1]
Granted (in dollars per share)	$ 32.69	[1]	$ 30.71	[1]	$ 32.69	[1]	$ 30.71	[1]
Vested (in dollars per share)					$ 22.45	[1]	$ 14.85	[1]
Forfeited (in dollars per share)	$ 32.40	[1]	$ 31.09	[1]	$ 32.72	[1]	$ 30.82	[1]
Outstanding, end of period (in dollars per share)	$ 32.88	[1]	$ 29.11	[1]	$ 32.88	[1]	$ 29.11	[1]
Total weighted-average grant-date fair value			100,000		3,000,000		2,500,000
Risk-free interest rate (as a percent)					0.38%		0.33%
Expected life					3 years		3 years
Expected volatility (as a percent)					19.40%		25.30%
Range of expected volatility for Peer Group, minimum (as a percent)					12.40%		15.50%
Range of expected volatility for Peer Group, maximum (as a percent)					25.30%		34.50%
Grant date fair value (in dollars per share)	$ 32.69		$ 30.71		$ 32.69		$ 30.71
Fair value of vested stock (in dollars)					2,200,000		600,000
Tax benefits					900,000		200,000
Amount of shares settled					70,205
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options Expirations in Period					17,548
Unrecognized compensation cost	2,900,000				2,900,000
Weighted-average period over which unrecognized compensation cost expected to be recognized					1 year 3 months 18 days
2011-2013 LTIP linked to TRS
Share-based compensation
Average period used to calculate performance goals					3 years
2012-2014 LTIP linked to TRS
Share-based compensation
Average period used to calculate performance goals					3 years
2013-2015 LTIP linked to TRS
Share-based compensation
Average period used to calculate performance goals					3 years
LTIP awards linked to other performance conditions
LTIP linked to TRS and other performance conditions (in shares)
Outstanding, beginning of period (in shares)	304,473		295,184		247,175		182,498
Granted (in shares)	1,504		4,148		120,399		122,852
Vested (in shares)					(18,280)
Cancelled (in shares)	0		(17,911)		(37,346)		(17,911)
Forfeited (in shares)	(4,881)		(3,676)		(10,852)		(9,694)
Outstanding, end of period (in shares)	301,096		277,745		301,096		277,745
Weighted-average grant-date fair value per share
Outstanding, beginning of period (in dollars per share)	$ 26.12	[2]	$ 23.95	[2]	$ 25.04	[2]	$ 22.63	[2]
Granted (in dollars per share)	$ 27.11	[2]	$ 27.30	[2]	$ 26.89	[2]	$ 26.05	[2]
Vested (in dollars per share)					$ 18.95	[2]
Cancelled (in dollars per share)	$ 0.00	[2]	$ 18.95	[2]	$ 24.96	[2]	$ 18.95	[2]
Forfeited (in dollars per share)	$ 26.53	[2]	$ 24.78	[2]	$ 26.20	[2]	$ 24.44	[2]
Outstanding, end of period (in dollars per share)	$ 26.12	[2]	$ 24.31	[2]	$ 26.12	[2]	$ 24.31	[2]
Total weighted-average grant-date fair value			100,000				3,200,000
Fair value of vested stock (in dollars)					600,000
Tax benefits					200,000
Unrecognized compensation cost	$ 3,700,000				$ 3,700,000
Weighted-average period over which unrecognized compensation cost expected to be recognized					1 year 4 months 24 days

[1] Weighted-average grant-date fair value per share determined using a Monte Carlo simulation model.

[2] Weighted-average grant-date fair value per share based on the average price of HEI common stock on the date of grant.