Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net Income	$ 34,276	$ 41,769	$ 117,872	$ 121,851
Other Comprehensive Income, Net of Tax:
Net Unrealized Gains on Investment Securities	7,051	403	4,735	15,291
Defined Benefit Plans	219	157	659	469
Total Other Comprehensive Income	7,270	560	5,394	15,760
Comprehensive Income	$ 41,546	$ 42,329	$ 123,266	$ 137,611