Bank subsidiary (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Noninterest expense
Income before income taxes	$ 76,769	$ 53,305	$ 163,122	$ 141,931
Income taxes	27,894	20,385	57,700	51,677
Net income	48,875	32,920	105,422	90,254
American Savings Bank (ASB)
Interest and dividend income
Interest and fees on loans	46,240	49,221	137,985	148,294
Interest and dividends on investment and mortgage-related securities	3,654	3,852	11,216	10,815
Total interest and dividend income	49,894	53,073	149,201	159,109
Interest expense
Interest on deposit liabilities	2,166	3,390	7,146	11,665
Interest on other borrowings	1,375	1,414	4,124	4,258
Total interest expense	3,541	4,804	11,270	15,923
Net interest income	46,353	48,269	137,931	143,186
Provision for loan losses	3,822	5,961	10,927	12,310
Net interest income after provision for loan losses	42,531	42,308	127,004	130,876
Noninterest income
Fee income on deposit liabilities	4,492	6,109	13,540	21,520
Fees from other financial services	7,219	6,781	21,405	19,844
Fee income on other financial products	1,806	1,697	5,340	4,957
Other income	2,689	3,769	8,245	8,545
Total noninterest income	16,206	18,356	48,530	54,866
Noninterest expense
Compensation and employee benefits	17,646	18,168	53,317	54,477
Occupancy	4,313	4,176	12,841	12,617
Data processing	2,451	2,019	6,479	10,921
Services	1,686	1,544	5,406	5,117
Equipment	1,712	1,600	5,141	4,949
Other expense	7,763	8,798	23,651	25,819
Total noninterest expense	35,571	36,305	106,835	113,900
Income before income taxes	23,166	24,359	68,699	71,842
Income taxes	7,709	9,066	24,196	26,682
Net income	$ 15,457	$ 15,293	$ 44,503	$ 45,160