Accumulated Other Comprehensive Income (Loss) (Other Comprehensive Income (Loss) Reclassification Adjustments) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income Loss [Line Items]
Pretax change before reclassifications	$ (31,030)	$ (27,633)	$ (59,176)	$ 28,332
Reclassifications out of AOCI	6,464	(7,907)	23,019	(2,618)
Tax effect	2,266	9,155	833	(12,505)
Other comprehensive (loss) income, net of tax	(22,300)	(26,385)	(35,324)	13,209
Unrealized Gains (Losses) on Securities
Accumulated Other Comprehensive Income Loss [Line Items]
Pretax change before reclassifications	(15,614)	(15,076)	(29,966)	35,317
Reclassifications out of AOCI	(108)	(9,241)	1,545	(16,689)
Tax effect	4,780	9,582	9,047	(7,124)
Other comprehensive (loss) income, net of tax	(10,942)	(14,735)	(19,374)	11,504
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income Loss [Line Items]
Pretax change before reclassifications	(15,416)	(12,557)	(29,210)	(6,985)
Other comprehensive (loss) income, net of tax	(15,416)	(12,557)	(29,210)	(6,985)
Pension Benefit Adjustment
Accumulated Other Comprehensive Income Loss [Line Items]
Reclassifications out of AOCI	6,572	1,334	21,474	14,071
Tax effect	(2,514)	(427)	(8,214)	(5,381)
Other comprehensive (loss) income, net of tax	$ 4,058	$ 907	$ 13,260	$ 8,690