Consolidated Statements of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Class A Common Stock	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Surplus	Surplus Class A Common Stock	Retained Earnings	Retained Earnings Class A Common Stock	Accumulated Other Comprehensive (Loss) Income	Accumulated Other Comprehensive (Loss) Income Class A Common Stock	Financial Instruments ASU cumulative effect adjustment	Financial Instruments ASU cumulative effect adjustment Retained Earnings	Financial Instruments ASU cumulative effect adjustment Accumulated Other Comprehensive (Loss) Income	Income tax ASU cumulative effect adjustment	Income tax ASU cumulative effect adjustment Retained Earnings	Income tax ASU cumulative effect adjustment Accumulated Other Comprehensive (Loss) Income
Shareholders' equity	$ 3,012,427		$ 11,005	$ 1,005	$ 658,918		$ 2,476,691		$ (135,192)
Net income	269,345		0	0	0		269,345		0
Other comprehensive income (loss), net of tax	42,868		0	0	0		0		42,868
Cash dividends	(10,809)		0	0	0		(10,809)		0
Shareholders' equity	3,313,831		11,005	1,005	658,918		2,735,227		(92,324)
Shareholders' equity	3,334,064		11,005	1,005	658,918		2,785,430		(122,294)
Net income	310,840		0	0	0		310,840		0
Other comprehensive income (loss), net of tax	(75,229)		0	0	0		0		(75,229)
Stock repurchased during period		$ (58,086)	(125)			$ (57,961)		$ 0		$ 0
Cash dividends	(12,576)		0	0	0		(12,576)		0
Cumulative effect of new accounting principle in period of adoption											$ 18,700	$ 18,716	$ (18,716)	$ 31,300	$ 31,336	$ (31,336)
Shareholders' equity	$ 3,499,013		$ 10,880	$ 1,005	$ 600,957		$ 3,133,746		$ (247,575)