Consolidated Statements of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Surplus	Retained Earnings	Accumulated Other Comprehensive Loss	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 tax ASU cumulative effect adjustment	Income tax ASU cumulative effect adjustment Retained Earnings	Income tax ASU cumulative effect adjustment Accumulated Other Comprehensive Loss
Shareholders' equity	$ 3,012,427	$ 11,005	$ 1,005	$ 658,918	$ 2,476,691	$ (135,192)
Net income	202,281	0	0	0	202,281	0
Other comprehensive income, net of tax	32,349	0	0	0	0	32,349
Cash dividends	(7,206)	0	0	0	(7,206)	0
Shareholders' equity	3,239,851	11,005	1,005	658,918	2,671,766	(102,843)
Shareholders' equity	3,334,064	11,005	1,005	658,918	2,785,430	(122,294)
Net income	193,522	0	0	0		0
Other comprehensive income, net of tax	(72,292)	0	0	0	0	(72,292)
Cash dividends	(8,408)	0	0	0	(8,408)	0
Cumulative Effect of New Accounting Principle in Period of Adoption							$ 18,700	$ 18,700	$ (18,700)	$ 31,300	$ 31,300	$ (31,300)
Shareholders' equity	$ 3,446,886	$ 11,005	$ 1,005	$ 658,918	$ 3,020,596	$ (244,638)