Note 6: Investment Securities: Schedule of Gross Unrealized Losses and Estimated Fair Value of Investments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Total Unrealized Losses And Estimated Fair Value
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 110,223	$ 198,302
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses	(3,548)	(6,554)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	65,295	39,255
Available for sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses	(848)	(395)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	175,518	237,557
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses	(4,396)	(6,949)
US Government Agencies Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	20,000	20,000
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses	(2,026)	(2,745)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	20,000	20,000
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses	(2,026)	(2,745)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	61,365	127,901
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses	(878)	(1,871)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	65,295	39,255
Available for sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses	(848)	(395)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	126,660	167,156
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses	(1,726)	(2,266)
US States and Political Subdivisions Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	28,858	50,401
Available For Sale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses	(644)	(1,938)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	28,858	50,401
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses	$ (644)	$ (1,938)