Fair value measurements (Details 3) (USD $)	Sep. 30, 2013 Level 2		Sep. 30, 2013 Level 2 Interest rate lock commitments		Sep. 30, 2013 Level 2 Forward sale contracts		Sep. 30, 2013 Level 1 Forward sale contracts		Sep. 30, 2013 Fair value measurements on a recurring basis Level 2 Bank	Dec. 31, 2012 Fair value measurements on a recurring basis Level 2 Bank	Sep. 30, 2013 Fair value measurements on a recurring basis Level 2 Other	Dec. 31, 2012 Fair value measurements on a recurring basis Level 2 Other	Sep. 30, 2013 Fair value measurements on a recurring basis Level 2 Mortgage-related securities - FNMA, FHLMC and GNMA Bank	Dec. 31, 2012 Fair value measurements on a recurring basis Level 2 Mortgage-related securities - FNMA, FHLMC and GNMA Bank	Sep. 30, 2013 Fair value measurements on a recurring basis Level 2 Federal agency obligations Bank	Dec. 31, 2012 Fair value measurements on a recurring basis Level 2 Federal agency obligations Bank	Sep. 30, 2013 Fair value measurements on a recurring basis Level 2 Municipal bonds Bank	Dec. 31, 2012 Fair value measurements on a recurring basis Level 2 Municipal bonds Bank	Sep. 30, 2013 Fair value measurements on a nonrecurring basis American Savings Bank (ASB)	Sep. 30, 2012 Fair value measurements on a nonrecurring basis American Savings Bank (ASB)	Sep. 30, 2013 Fair value measurements on a nonrecurring basis Estimated fair value	Dec. 31, 2012 Fair value measurements on a nonrecurring basis Estimated fair value	Sep. 30, 2013 Fair value measurements on a nonrecurring basis Level 3	Dec. 31, 2012 Fair value measurements on a nonrecurring basis Level 3
Fair value measurements on a recurring and nonrecurring basis
Money market funds											$ 10,000	$ 10,000
Available-for-sale securities									535,264,000	671,358,000			357,977,000	417,383,000	98,265,000	171,491,000	79,022,000	82,484,000
Derivative assets
Derivative assets	558,000	[1]	556,000	[1]	2,000	[1]
Derivative liabilities					73,000	[1]	202,000	[1]
Loans																					5,000,000	21,000,000	5,000,000	21,000,000
Real estate acquired in settlement of loans																					0	3,000,000	0	3,000,000
Adjustments to fair value of loans held for sale																			$ 0	$ 0

[1] Derivatives are carried at fair value with changes in value reflected in the balance sheet in other assets or other liabilities and included in mortgage banking income.