Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Consolidated Statements of Comprehensive Income
Net income	$ 264,394	$ 183,682	$ 230,178
Other comprehensive loss, net of tax:
Net change in pensions and other benefits	2,960	4,291	(3,354)
Net change in investment securities	(14,259)	(14,159)	(34,852)
Net change in cash flow derivative hedges	(4,445)	1,496	1,454
Other comprehensive loss	(15,744)	(8,372)	(36,752)
Total comprehensive income	$ 248,650	$ 175,310	$ 193,426