Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Comprehensive Income [Abstract]
Unrealized gains on available-for-sale securities, taxes	$ 3,848	$ (1,005)	$ (5,590)
Other Comprehensive Income Loss Transfers From Available For Sale To Held To Maturity, Tax	(172)	(193)	518
Other Comprehensive Income Loss Reclassification Adjustment For Sale Or Writedown Of Securities Included In Net Income Tax	465	176	279
Other Than Temporary Impairment Losses recognized in earnings, tax	0	0	0
Unrealized gains (losses) on available-for-sale securities for which a portion of an other-than-temporary impairment has been recognized in income, taxes	$ 0	$ 0	$ 0