Bank subsidiary (Details 3) (USD $)	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
Assets
Available-for-sale investment and mortgage-related securities	$ 631,063,000	$ 624,331,000
Investment in stock of Federal Home Loan Bank of Seattle	97,764,000	97,764,000
Loans receivable held for investment, net	3,672,401,000	3,642,818,000
Loans held for sale, at lower of cost or fair value	14,657,000	9,601,000
Other	538,443,000	517,550,000
Goodwill	82,190,000	82,190,000
Total assets	9,632,952,000	9,592,731,000
Liabilities and shareholders' equity
Other	456,817,000	516,990,000
Total liabilities	8,044,561,000	8,026,489,000
Common stock	1,362,880,000	1,349,446,000
Retained earnings	210,044,000	201,640,000
Accumulated other comprehensive loss, net of tax benefits	(18,826,000)	(19,137,000)
Total shareholders' equity	1,554,098,000	1,531,949,000	1,496,551,000	1,483,637,000
Total liabilities and shareholders' equity	9,632,952,000	9,592,731,000
Other assets
Premises and equipment, net	3,375,654,000	3,334,501,000
Total other assets	538,443,000	517,550,000
Other liabilities
Total other liabilities	456,817,000	516,990,000
American Savings Bank (ASB)
Assets
Cash and cash equivalents	229,635,000	219,678,000
Available-for-sale investment and mortgage-related securities	631,063,000	624,331,000
Investment in stock of Federal Home Loan Bank of Seattle	97,764,000	97,764,000
Loans receivable held for investment, net	3,672,401,000	3,642,818,000
Loans held for sale, at lower of cost or fair value	14,657,000	9,601,000
Other	235,407,000	233,592,000
Goodwill	82,190,000	82,190,000
Total assets	4,963,117,000	4,909,974,000
Liabilities and shareholders' equity
Deposit liabilities-noninterest-bearing	1,054,512,000	993,828,000
Deposit liabilities-interest-bearing	3,070,692,000	3,076,204,000
Other borrowings	232,843,000	233,229,000
Other	110,117,000	118,078,000
Total liabilities	4,468,164,000	4,421,339,000
Common stock	332,299,000	331,880,000
Retained earnings	172,003,000	166,126,000
Accumulated other comprehensive loss, net of tax benefits	(9,349,000)	(9,371,000)
Total shareholders' equity	494,953,000	488,635,000
Total liabilities and shareholders' equity	4,963,117,000	4,909,974,000
Other assets
Bank-owned life insurance	122,631,000	121,470,000
Premises and equipment, net	53,217,000	52,940,000
Prepaid expenses	15,957,000	15,297,000
Accrued interest receivable	14,186,000	14,190,000
Mortgage-servicing rights	8,582,000	8,227,000
Real estate acquired in settlement of loans, net	6,091,000	7,260,000
Other	14,743,000	14,208,000
Total other assets	235,407,000	233,592,000
Other liabilities
Accrued expenses	12,124,000	21,216,000
Federal and state income taxes payable	42,598,000	35,002,000
Cashier's checks	22,410,000	22,802,000
Advance payments by borrowers	6,464,000	10,100,000
Other	26,521,000	28,958,000
Total other liabilities	110,117,000	118,078,000
Balance Sheet related disclosures
Securities sold under agreements to repurchase	183,000,000	183,000,000
Advances from Federal Home Loan Bank	50,000,000	50,000,000
Loan commitments and unused lines and letters of credit	1,400,000,000
Commitments to borrowers whose loan terms are modified under troubled debt restructuring	$ 3,000,000