Bank segment - Income statement data (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Noninterest expense
Income before income taxes	$ 56,402	$ 65,071	$ 108,720		$ 137,052
Income taxes	20,911	23,317	40,890		49,038
Net income	35,491	41,754	67,830	[1]	88,014	[1]
American Savings Bank (ASB)
Interest and dividend income
Interest and fees on loans	46,035	43,851	91,233		87,533
Interest and dividend on investment securities	3,306	2,950	6,357		5,985
Total interest and dividend income	49,341	46,801	97,590		93,518
Interest expense
Interest on deposit liabilities	1,266	1,237	2,526		2,462
Interest on other borrowings	1,487	1,420	2,953		2,825
Total interest expense	2,753	2,657	5,479		5,287
Net interest income	46,588	44,144	92,111		88,231
Provision for loan losses	1,825	1,021	2,439		2,016
Net interest income after provision for loan losses	44,763	43,123	89,672		86,215
Noninterest income
Fees from other financial services	5,550	5,217	10,905		10,345
Fee income on deposit liabilities	5,424	4,645	10,739		9,066
Fee income on other financial products	2,103	2,064	3,992		4,354
Bank-owned life insurance	1,058	982	2,041		1,945
Mortgage banking income	2,068	246	3,890		874
Gains on sale of securities	0	0	0		2,847
Other income	239	661	974		1,286
Total noninterest income	16,442	13,815	32,541		30,717
Noninterest expense
Compensation and employee benefits	22,319	19,872	44,085		40,158
Occupancy	4,009	4,489	8,122		8,442
Data processing	2,953	2,971	6,069		6,031
Services	2,833	2,855	5,174		5,128
Equipment	1,690	1,609	3,391		3,254
Office supplies, printing and postage	1,303	1,456	2,786		3,072
Marketing	844	1,031	1,685		1,742
Federal Deposit Insurance Corporation Premium Expense	773	805	1,584		1,601
Other expense	4,755	3,894	8,960		7,016
Total noninterest expense	41,479	38,982	81,856		76,444
Income before income taxes	19,726	17,956	40,357		40,488
Income taxes	6,875	6,420	14,031		14,553
Net income	$ 12,851	$ 11,536	$ 26,326		$ 25,935

[1] As restated - See Note 1, “Basis of presentation - Restatement of previously issued financial statements.”