Bank segment (Details 3) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Assets
Available-for-sale investment and mortgage-related securities	$ 549,321,000	$ 529,007,000
Investment in stock of Federal Home Loan Bank of Seattle	80,863,000	92,546,000
Loans receivable held for investment, net	4,245,240,000	4,110,113,000
Loans held for sale, at lower of cost or fair value	956,000	5,302,000
Other	557,684,000	512,627,000
Goodwill	82,190,000	82,190,000
Total assets	10,617,143,000	10,340,044,000
Liabilities and shareholders' equity
Other	494,834,000	524,224,000
Total liabilities	8,821,971,000	8,578,681,000
Common stock	1,493,436,000	1,488,126,000
Retained earnings	280,126,000	255,694,000
Accumulated other comprehensive income (loss), net of taxes:
Accumulated other comprehensive loss, net of taxes	(12,683,000)	(16,750,000)	(34,789,000)	(26,423,000)
Common stock equity	1,760,879,000	1,727,070,000	1,624,649,000	1,593,865,000
Total liabilities and shareholders’ equity	10,617,143,000	10,340,044,000
Other assets
Property, plant and equipment, net of accumulated depreciation	3,980,096,000	3,865,514,000
Other assets	557,684,000	512,627,000
Other liabilities
Total other liabilities	494,834,000	524,224,000
Balance Sheet related disclosures
Securities sold under agreements to repurchase	142,000,000	145,000,000
American Savings Bank (ASB)
Assets
Cash and cash equivalents	174,950,000	156,603,000
Available-for-sale investment and mortgage-related securities	549,321,000	529,007,000
Investment in stock of Federal Home Loan Bank of Seattle	80,863,000	92,546,000
Loans receivable held for investment	4,287,612,000	4,150,229,000
Allowance for loan losses	(42,372,000)	(40,116,000)
Loans receivable held for investment, net	4,245,240,000	4,110,113,000
Loans held for sale, at lower of cost or fair value	956,000	5,302,000
Other	284,607,000	268,063,000
Goodwill	82,190,000	82,190,000
Total assets	5,418,127,000	5,243,824,000
Liabilities and shareholders' equity
Deposit liabilities-noninterest-bearing	1,301,758,000	1,214,418,000
Deposit liabilities-interest-bearing	3,223,102,000	3,158,059,000
Other borrowings	242,455,000	244,514,000
Other	116,953,000	105,679,000
Total liabilities	4,884,268,000	4,722,670,000
Common stock	337,262,000	336,054,000
Retained earnings	205,012,000	197,297,000
Accumulated other comprehensive income (loss), net of taxes:
Net unrealized losses on securities	(315,000)	(3,663,000)
Accumulated other comprehensive loss, net of tax benefits	(8,100,000)	(8,534,000)
Accumulated other comprehensive loss, net of taxes	(8,415,000)	(12,197,000)
Common stock equity	533,859,000	521,154,000
Total liabilities and shareholders’ equity	5,418,127,000	5,243,824,000
Other assets
Bank-owned life insurance	131,959,000	129,963,000
Property, plant and equipment, net of accumulated depreciation	68,254,000	67,766,000
Prepaid expenses	3,878,000	3,616,000
Accrued interest receivable	13,354,000	13,133,000
Mortgage-servicing rights	11,605,000	11,687,000
Equity Investments, Affordable Housing Program	23,820,000	14,543,000
Real estate acquired in settlement of loans, net	1,045,000	1,205,000
Other	30,692,000	26,150,000
Other assets	284,607,000	268,063,000
Other liabilities
Accrued expenses	24,440,000	19,989,000
Federal and state income taxes payable	38,940,000	37,807,000
Cashier's checks	21,286,000	21,110,000
Advance payments by borrowers	9,852,000	9,647,000
Other	22,435,000	17,126,000
Total other liabilities	116,953,000	105,679,000
Balance Sheet related disclosures
Securities sold under agreements to repurchase	142,000,000	145,000,000
Advances from Federal Home Loan Bank	$ 100,000,000	$ 100,000,000