Bank subsidiary (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Noninterest expense
Income before income taxes	$ 71,548	$ 73,981	$ 189,077	$ 196,165
Income taxes	22,841	25,804	65,157	69,926
Net income	48,707	48,177	123,920	126,239
American Savings Bank (ASB)
Interest and dividend income
Interest and fees on loans	43,337	43,880	129,564	133,241
Interest and dividend on investment and mortgage-related securities	3,025	3,432	9,723	10,534
Total interest and dividend income	46,362	47,312	139,287	143,775
Interest expense
Interest on deposit liabilities	1,262	1,540	3,870	5,015
Interest on other borrowings	1,206	1,201	3,548	3,676
Total interest expense	2,468	2,741	7,418	8,691
Net interest income	43,894	44,571	131,869	135,084
Provision for loan losses	54	3,580	953	9,504
Net interest income after provision for loan losses	43,840	40,991	130,916	125,580
Noninterest income
Fees from other financial services	5,728	7,674	21,367	22,474
Fee income on deposit liabilities	4,819	4,527	13,566	13,127
Fee income on other financial products	2,714	1,660	6,288	4,741
Mortgage banking income	1,547	4,077	6,896	8,297
Gains on sale of securities	0	0	1,226	134
Other income	3,888	1,346	7,211	4,021
Total noninterest income	18,696	19,284	56,554	52,794
Noninterest expense
Compensation and employee benefits	20,564	18,684	60,715	56,026
Occupancy	4,208	4,400	12,550	12,866
Data processing	2,168	2,644	7,982	7,244
Services	2,424	3,062	6,855	7,066
Equipment	1,825	1,762	5,469	5,299
Other expense	8,539	8,096	24,634	22,909
Total noninterest expense	39,728	38,648	118,205	111,410
Income before income taxes	22,808	21,627	69,265	66,964
Income taxes	7,532	7,419	23,915	22,690
Net income	$ 15,276	$ 14,208	$ 45,350	$ 44,274