Fair value measurements (Details 3) (USD $)	Jun. 30, 2013 Level 2	Jun. 30, 2013 Level 2 Interest rate lock commitments	Jun. 30, 2013 Level 2 Forward sale contracts	Jun. 30, 2013 Level 1	Jun. 30, 2013 Level 1 Forward sale contracts	Jun. 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	Jun. 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	Jun. 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	Jun. 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	Jun. 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	Jun. 30, 2013 Fair value measurements on a nonrecurring basis American Savings Bank (ASB)	Jun. 30, 2012 Fair value measurements on a nonrecurring basis American Savings Bank (ASB)	Jun. 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	Jun. 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						560,172,000	671,358,000			382,044,000	417,383,000	99,064,000	171,491,000	79,064,000	82,484,000
Derivative assets
Derivative assets	538,000	211,000	327,000	625,000	625,000
Derivative liabilities
Derivative liabilities	525,000	473,000	52,000
Loans																		17,000,000	21,000,000	17,000,000	21,000,000
Real estate acquired in settlement of loans																		2,000,000	3,000,000	2,000,000	3,000,000
Adjustments to fair value of loans held for sale																$ 0	$ 0