Note 2: Investments in Securities: Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 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	$ 65,494	$ 40,042
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(567)	(328)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	10,545	65,981
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(254)	(986)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	76,039	106,023
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	(821)	(1,314)
US Government Agencies Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	20,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(219)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		20,000
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss		(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	(219)	(486)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	45,494	40,042
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(348)	(328)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	9,635	45,056
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(253)	(493)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	55,129	85,098
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	(601)	(821)
US States and Political Subdivisions Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	910	925
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(1)	(7)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	910	925
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	$ (1)	$ (7)