Loans Receivable and The Allowance For Loan Losses: Schedule of Impaired Loans With and Without Specific Allowance Reserves (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Total without a specific allowance reserve
Impaired Financing Receivable, Recorded Investment	$ 46,227	$ 48,398
Impaired Financing Receivable, Unpaid Principal Balance	50,804	50,851
Impaired Financing Receivable, Related Allowance	3,391	3,283
Impaired Financing Receivable, Average Recorded Investment	47,093	50,493
Impaired Financing Receivable Interest Income Recognized	905	1,411
Total with a specific allowance reserve
Impaired Financing Receivable, Recorded Investment	59,145	81,447
Impaired Financing Receivable, Unpaid Principal Balance	68,080	100,896
Impaired Financing Receivable, Related Allowance	6,971	7,033
Impaired Financing Receivable, Average Recorded Investment	62,125	101,787
Impaired Financing Receivable Interest Income Recognized	752	1,647
Total impaired loans with and without a specific allowance reserve
Impaired Financing Receivable, Recorded Investment	105,372	129,845
Impaired Financing Receivable, Unpaid Principal Balance	118,884	151,747
Impaired Financing Receivable, Related Allowance	10,362	10,316
Impaired Financing Receivable, Average Recorded Investment	109,218	152,280
Impaired Financing Receivable Interest Income Recognized	1,657	3,058
Without a specific allowance reserve | Consumer
Impaired Financing Receivable, Recorded Investment	736	559
Impaired Financing Receivable, Unpaid Principal Balance	844	666
Impaired Financing Receivable, Related Allowance	10	5
Impaired Financing Receivable, Average Recorded Investment	789	624
Impaired Financing Receivable Interest Income Recognized	6	7
Without a specific allowance reserve | Consumer secured by one- to four-family
Impaired Financing Receivable, Recorded Investment	1,798	1,707
Impaired Financing Receivable, Unpaid Principal Balance	2,104	2,162
Impaired Financing Receivable, Related Allowance	54	29
Impaired Financing Receivable, Average Recorded Investment	1,794	2,042
Impaired Financing Receivable Interest Income Recognized	13	22
Without a specific allowance reserve | Total consumer
Impaired Financing Receivable, Recorded Investment		2,266
Impaired Financing Receivable, Unpaid Principal Balance		2,828
Impaired Financing Receivable, Related Allowance		34
Impaired Financing Receivable, Average Recorded Investment		2,666
Impaired Financing Receivable Interest Income Recognized		29
Without a specific allowance reserve | Commercial real estate owner occupied
Impaired Financing Receivable, Recorded Investment	1,581	852
Impaired Financing Receivable, Unpaid Principal Balance	1,922	853
Impaired Financing Receivable, Related Allowance	124	78
Impaired Financing Receivable, Average Recorded Investment	1,581	874
Without a specific allowance reserve | Commercial real estate investment properties
Impaired Financing Receivable, Recorded Investment	1,216	1,576
Impaired Financing Receivable, Unpaid Principal Balance	1,523	1,618
Impaired Financing Receivable, Related Allowance	223	261
Impaired Financing Receivable, Average Recorded Investment	1,349	1,728
Impaired Financing Receivable Interest Income Recognized	10	9
Without a specific allowance reserve | Multifamily real estate
Impaired Financing Receivable, Recorded Investment	2,136	452
Impaired Financing Receivable, Unpaid Principal Balance	2,136	452
Impaired Financing Receivable, Related Allowance	482	6
Impaired Financing Receivable, Average Recorded Investment	2,139	456
Impaired Financing Receivable Interest Income Recognized	56	32
Without a specific allowance reserve | One- to four-family construction
Impaired Financing Receivable, Recorded Investment	5,481	5,429
Impaired Financing Receivable, Unpaid Principal Balance	5,543	5,488
Impaired Financing Receivable, Related Allowance	435	437
Impaired Financing Receivable, Average Recorded Investment	5,286	5,580
Impaired Financing Receivable Interest Income Recognized	119	242
Without a specific allowance reserve | Land development residential
Impaired Financing Receivable, Recorded Investment	1,158	4,064
Impaired Financing Receivable, Unpaid Principal Balance	2,201	4,679
Impaired Financing Receivable, Related Allowance	420	1,176
Impaired Financing Receivable, Average Recorded Investment	1,338	4,524
Impaired Financing Receivable Interest Income Recognized		99
Without a specific allowance reserve | Land development commercial
Impaired Financing Receivable, Recorded Investment	89	645
Impaired Financing Receivable, Unpaid Principal Balance	89	645
Impaired Financing Receivable, Related Allowance	19	45
Impaired Financing Receivable, Average Recorded Investment	90	616
Without a specific allowance reserve | Commercial business
Impaired Financing Receivable, Recorded Investment	6,886	5,173
Impaired Financing Receivable, Unpaid Principal Balance	7,439	5,535
Impaired Financing Receivable, Related Allowance	1,288	932
Impaired Financing Receivable, Average Recorded Investment	7,109	5,587
Impaired Financing Receivable Interest Income Recognized	110	81
Without a specific allowance reserve | Agricultural business
Impaired Financing Receivable, Recorded Investment	1,010	412
Impaired Financing Receivable, Unpaid Principal Balance	1,693	632
Impaired Financing Receivable, Related Allowance	103	37
Impaired Financing Receivable, Average Recorded Investment	1,427	529
Without a specific allowance reserve | One- to four-family residential
Impaired Financing Receivable, Recorded Investment	24,136	27,529
Impaired Financing Receivable, Unpaid Principal Balance	25,310	28,121
Impaired Financing Receivable, Related Allowance	233	277
Impaired Financing Receivable, Average Recorded Investment	24,191	27,933
Impaired Financing Receivable Interest Income Recognized	590	919
With a specific allowance reserve | Consumer
Impaired Financing Receivable, Recorded Investment	989	915
Impaired Financing Receivable, Unpaid Principal Balance	1,047	915
Impaired Financing Receivable, Related Allowance	33	62
Impaired Financing Receivable, Average Recorded Investment	1,034	881
Impaired Financing Receivable Interest Income Recognized	18	18
With a specific allowance reserve | Consumer secured by one- to four-family
Impaired Financing Receivable, Recorded Investment	591	603
Impaired Financing Receivable, Unpaid Principal Balance	689	630
Impaired Financing Receivable, Average Recorded Investment	673	585
With a specific allowance reserve | Total consumer
Impaired Financing Receivable, Recorded Investment		1,518
Impaired Financing Receivable, Unpaid Principal Balance		1,545
Impaired Financing Receivable, Related Allowance		62
Impaired Financing Receivable, Average Recorded Investment		1,466
Impaired Financing Receivable Interest Income Recognized		18
With a specific allowance reserve | Commercial real estate owner occupied
Impaired Financing Receivable, Recorded Investment	2,802	3,643
Impaired Financing Receivable, Unpaid Principal Balance	3,060	4,013
Impaired Financing Receivable, Related Allowance	3	207
Impaired Financing Receivable, Average Recorded Investment	2,894	3,901
Impaired Financing Receivable Interest Income Recognized	14	13
With a specific allowance reserve | Commercial real estate investment properties
Impaired Financing Receivable, Recorded Investment	6,666	11,750
Impaired Financing Receivable, Unpaid Principal Balance	7,774	14,200
Impaired Financing Receivable, Related Allowance	397	1,485
Impaired Financing Receivable, Average Recorded Investment	6,980	13,471
Impaired Financing Receivable Interest Income Recognized	69	424
With a specific allowance reserve | Multifamily real estate
Impaired Financing Receivable, Recorded Investment	5,000	1,997
Impaired Financing Receivable, Unpaid Principal Balance	5,000	1,997
Impaired Financing Receivable, Related Allowance	1,464	11
Impaired Financing Receivable, Average Recorded Investment	5,000	1,967
Impaired Financing Receivable Interest Income Recognized	130	82
With a specific allowance reserve | One- to four-family construction
Impaired Financing Receivable, Recorded Investment	7,706	9,556
Impaired Financing Receivable, Unpaid Principal Balance	7,706	9,821
Impaired Financing Receivable, Related Allowance	2,450	1,998
Impaired Financing Receivable, Average Recorded Investment	7,565	9,185
Impaired Financing Receivable Interest Income Recognized	149	277
With a specific allowance reserve | Land development residential
Impaired Financing Receivable, Recorded Investment	3,594	20,331
Impaired Financing Receivable, Unpaid Principal Balance	8,158	34,068
Impaired Financing Receivable, Related Allowance	289	616
Impaired Financing Receivable, Average Recorded Investment	4,667	36,747
Impaired Financing Receivable Interest Income Recognized		220
With a specific allowance reserve | Land development commercial
Impaired Financing Receivable, Recorded Investment	294	454
Impaired Financing Receivable, Unpaid Principal Balance	454	454
Impaired Financing Receivable, Average Recorded Investment	428	454
With a specific allowance reserve | Commercial business
Impaired Financing Receivable, Recorded Investment	10,514	12,889
Impaired Financing Receivable, Unpaid Principal Balance	11,902	13,333
Impaired Financing Receivable, Related Allowance	1,054	1,404
Impaired Financing Receivable, Average Recorded Investment	12,296	13,721
Impaired Financing Receivable Interest Income Recognized	115	144
With a specific allowance reserve | Agricultural business
Impaired Financing Receivable, Recorded Investment		1,483
Impaired Financing Receivable, Unpaid Principal Balance		1,671
Impaired Financing Receivable, Related Allowance		592
Impaired Financing Receivable, Average Recorded Investment		1,855
With a specific allowance reserve | One- to four-family residential
Impaired Financing Receivable, Recorded Investment	20,989	16,877
Impaired Financing Receivable, Unpaid Principal Balance	22,290	18,301
Impaired Financing Receivable, Related Allowance	1,281	658
Impaired Financing Receivable, Average Recorded Investment	20,588	17,555
Impaired Financing Receivable Interest Income Recognized	257	469
With a specific allowance reserve | Commercial construction
Impaired Financing Receivable, Recorded Investment		949
Impaired Financing Receivable, Unpaid Principal Balance		1,493
Impaired Financing Receivable, Average Recorded Investment		1,465
Total with and without a specific allowance reserve | Consumer
Impaired Financing Receivable, Recorded Investment	1,724	1,474
Impaired Financing Receivable, Unpaid Principal Balance	1,890	1,581
Impaired Financing Receivable, Related Allowance	43	67
Impaired Financing Receivable, Average Recorded Investment	1,823	1,505
Impaired Financing Receivable Interest Income Recognized	24	25
Total with and without a specific allowance reserve | Consumer secured by one- to four-family
Impaired Financing Receivable, Recorded Investment	2,388	2,310
Impaired Financing Receivable, Unpaid Principal Balance	2,793	2,792
Impaired Financing Receivable, Related Allowance	54	29
Impaired Financing Receivable, Average Recorded Investment	2,467	2,627
Impaired Financing Receivable Interest Income Recognized	13	22
Total with and without a specific allowance reserve | Total consumer
Impaired Financing Receivable, Recorded Investment		3,784
Impaired Financing Receivable, Unpaid Principal Balance		4,373
Impaired Financing Receivable, Related Allowance		96
Impaired Financing Receivable, Average Recorded Investment		4,132
Impaired Financing Receivable Interest Income Recognized		47
Total with and without a specific allowance reserve | Commercial real estate owner occupied
Impaired Financing Receivable, Recorded Investment	4,383	4,495
Impaired Financing Receivable, Unpaid Principal Balance	4,982	4,866
Impaired Financing Receivable, Related Allowance	127	285
Impaired Financing Receivable, Average Recorded Investment	4,475	4,775
Impaired Financing Receivable Interest Income Recognized	14	13
Total with and without a specific allowance reserve | Commercial real estate investment properties
Impaired Financing Receivable, Recorded Investment	7,882	13,326
Impaired Financing Receivable, Unpaid Principal Balance	9,298	15,818
Impaired Financing Receivable, Related Allowance	620	1,746
Impaired Financing Receivable, Average Recorded Investment	8,329	15,199
Impaired Financing Receivable Interest Income Recognized	79	433
Total with and without a specific allowance reserve | Multifamily real estate
Impaired Financing Receivable, Recorded Investment	7,136	2,449
Impaired Financing Receivable, Unpaid Principal Balance	7,136	2,449
Impaired Financing Receivable, Related Allowance	1,946	17
Impaired Financing Receivable, Average Recorded Investment	7,139	2,423
Impaired Financing Receivable Interest Income Recognized	187	114
Total with and without a specific allowance reserve | One- to four-family construction
Impaired Financing Receivable, Recorded Investment	13,187	14,985
Impaired Financing Receivable, Unpaid Principal Balance	13,249	15,309
Impaired Financing Receivable, Related Allowance	2,885	2,435
Impaired Financing Receivable, Average Recorded Investment	12,851	14,765
Impaired Financing Receivable Interest Income Recognized	268	519
Total with and without a specific allowance reserve | Land development residential
Impaired Financing Receivable, Recorded Investment	4,752	24,395
Impaired Financing Receivable, Unpaid Principal Balance	10,359	38,747
Impaired Financing Receivable, Related Allowance	709	1,792
Impaired Financing Receivable, Average Recorded Investment	6,005	41,271
Impaired Financing Receivable Interest Income Recognized		319
Total with and without a specific allowance reserve | Land development commercial
Impaired Financing Receivable, Recorded Investment	383	1,099
Impaired Financing Receivable, Unpaid Principal Balance	543	1,099
Impaired Financing Receivable, Related Allowance	19	45
Impaired Financing Receivable, Average Recorded Investment	518	1,070
Total with and without a specific allowance reserve | Commercial business
Impaired Financing Receivable, Recorded Investment	17,400	18,062
Impaired Financing Receivable, Unpaid Principal Balance	19,341	18,868
Impaired Financing Receivable, Related Allowance	2,342	2,336
Impaired Financing Receivable, Average Recorded Investment	19,405	19,308
Impaired Financing Receivable Interest Income Recognized	225	225
Total with and without a specific allowance reserve | Agricultural business
Impaired Financing Receivable, Recorded Investment	1,011	1,895
Impaired Financing Receivable, Unpaid Principal Balance	1,693	2,303
Impaired Financing Receivable, Related Allowance	103	629
Impaired Financing Receivable, Average Recorded Investment	1,427	2,384
Total with and without a specific allowance reserve | One- to four-family residential
Impaired Financing Receivable, Recorded Investment	45,126	44,406
Impaired Financing Receivable, Unpaid Principal Balance	47,600	46,422
Impaired Financing Receivable, Related Allowance	1,514	935
Impaired Financing Receivable, Average Recorded Investment	44,779	45,488
Impaired Financing Receivable Interest Income Recognized	847	1,388
Total with and without a specific allowance reserve | Commercial construction
Impaired Financing Receivable, Recorded Investment		949
Impaired Financing Receivable, Unpaid Principal Balance		1,493
Impaired Financing Receivable, Average Recorded Investment		$ 1,465