Note 6: Investment Securities: Schedule of Gross Unrealized Losses and Estimated Fair Value of Investments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 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	$ 54,003	$ 198,302
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(522)	(6,554)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	77,447	39,255
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(2,000)	(395)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	131,450	237,557
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	(2,522)	(6,949)
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		(2,745)
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	(1,063)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	20,000	20,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	(1,063)	(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	51,442	127,901
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(514)	(1,871)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	46,054	39,255
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(719)	(395)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	97,496	167,156
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	(1,233)	(2,266)
US States and Political Subdivisions Debt Securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	2,561	50,401
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	(8)	(1,938)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	11,393
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss	(218)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	13,954	50,401
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss	$ (226)	$ (1,938)