Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands, shares in Millions	Total	Common stock [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss), net of tax [Member]	Treasury stock, at cost [Member]	Common shares outstanding [Member]
Balance, beginning of period at Dec. 31, 2020		$ 23,743,000	$ 38,771,000	$ 2,502,000	$ (35,815,000)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		214,000
Compensation amortization under share-based plans and other changes		127,000
Net income	$ 2,329,000		2,329,000
Dividends			(660,000)
Other			(2,000)
Other comprehensive loss	(1,336,000)			(1,336,000)
Treasury stock acquired — share repurchase authorizations					(1,356,000)
Net shares acquired related to employee share-based compensation plans					(43,000)
Balance, end of period at Sep. 30, 2021	28,474,000	24,084,000	40,438,000	1,166,000	(37,214,000)
Balance, beginning of year (in shares) at Dec. 31, 2020						252.4
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)						(8.8)
Net shares issued under employee share-based compensation plans (in shares)						2.4
Balance, end of period (in shares) at Sep. 30, 2021						246.0
Balance, beginning of period at Jun. 30, 2021		24,002,000	39,998,000	1,769,000	(36,613,000)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		45,000
Compensation amortization under share-based plans and other changes		37,000
Net income	662,000		662,000
Dividends			(220,000)
Other			(2,000)
Other comprehensive loss	(603,000)			(603,000)
Treasury stock acquired — share repurchase authorizations					(600,000)
Net shares acquired related to employee share-based compensation plans					(1,000)
Balance, end of period at Sep. 30, 2021	28,474,000	24,084,000	40,438,000	1,166,000	(37,214,000)
Balance, beginning of year (in shares) at Jun. 30, 2021						249.5
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)						(3.8)
Net shares issued under employee share-based compensation plans (in shares)						0.3
Balance, end of period (in shares) at Sep. 30, 2021						246.0
Balance, beginning of period at Dec. 31, 2021	28,887,000	24,154,000	41,555,000	1,193,000	(38,015,000)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		176,000
Compensation amortization under share-based plans and other changes		142,000
Net income	2,023,000		2,023,000
Dividends			(660,000)
Other			(1,000)
Other comprehensive loss	(9,101,000)			(9,101,000)
Treasury stock acquired — share repurchase authorizations	(1,500,000)				(1,500,000)
Net shares acquired related to employee share-based compensation plans	(60,000)				(60,000)
Balance, end of period at Sep. 30, 2022	$ 19,906,000	24,472,000	42,917,000	(7,908,000)	(39,575,000)
Balance, beginning of year (in shares) at Dec. 31, 2021	241.2					241.2
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)	(8.9)					(8.9)
Net shares issued under employee share-based compensation plans (in shares)						2.0
Balance, end of period (in shares) at Sep. 30, 2022	234.3					234.3
Balance, beginning of period at Jun. 30, 2022		24,419,000	42,684,000	(5,155,000)	(39,074,000)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		11,000
Compensation amortization under share-based plans and other changes		42,000
Net income	$ 454,000		454,000
Dividends			(221,000)
Other			0
Other comprehensive loss	(2,753,000)			(2,753,000)
Treasury stock acquired — share repurchase authorizations	(500,000)				(500,000)
Net shares acquired related to employee share-based compensation plans	(715)				(1,000)
Balance, end of period at Sep. 30, 2022	$ 19,906,000	$ 24,472,000	$ 42,917,000	$ (7,908,000)	$ (39,575,000)
Balance, beginning of year (in shares) at Jun. 30, 2022						237.3
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)	(3.1)					(3.1)
Net shares issued under employee share-based compensation plans (in shares)						0.1
Balance, end of period (in shares) at Sep. 30, 2022	234.3					234.3