Note 6: Investment Securities: Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Total Unrealized Losses And Estimated Fair Value
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 21,559	$ 40,042
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(118)	(328)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	64,250	65,981
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(644)	(986)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	85,809	106,023
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	(762)	(1,314)
US Government Agencies Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	20,000	20,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(197)	(486)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	20,000	20,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	(197)	(486)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	19,004	40,042
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(93)	(328)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	43,333	45,056
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(433)	(493)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	62,337	85,098
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	(526)	(821)
US States and Political Subdivisions Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	2,555
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(25)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	917	925
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(14)	(7)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	3,472	925
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	$ (39)	$ (7)