Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Consolidated Statements of Comprehensive Income
Net income	$ 54,860	$ 54,558	$ 120,391	$ 108,680
Net change in pension and other benefits	(46)		(46)
Net unrealized gains (losses) on available-for-sale securities	13,067	(10,396)	46,455	6,204
Net unrealized gains (losses) on cash flow derivative hedges	125	499	(377)	(114)
Other comprehensive income (loss)	13,146	(9,897)	46,032	6,090
Total comprehensive income	$ 68,006	$ 44,661	$ 166,423	$ 114,770