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, 2021		$ 24,154,000	$ 41,555,000	$ 1,193,000	$ (38,015,000)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		165,000
Compensation amortization under share-based plans and other changes		100,000
Net income (loss)	$ 1,569,000		1,569,000
Dividends			(439,000)
Other			(1,000)
Other comprehensive income (loss)	(6,348,000)			(6,348,000)
Treasury stock acquired — share repurchase authorizations					(1,000,000)
Net shares acquired related to employee share-based compensation plans					(59,000)
Balance, end of period at Jun. 30, 2022	22,874,000	24,419,000	42,684,000	(5,155,000)	(39,074,000)
Balance, beginning of period (in shares) at Dec. 31, 2021						241.2
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)						(5.8)
Net shares issued under employee share-based compensation plans (in shares)						1.9
Balance, end of period (in shares) at Jun. 30, 2022						237.3
Balance, beginning of period at Mar. 31, 2022		24,348,000	42,359,000	(2,602,000)	(38,574,000)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		30,000
Compensation amortization under share-based plans and other changes		41,000
Net income (loss)	551,000		551,000
Dividends			(225,000)
Other			(1,000)
Other comprehensive income (loss)	(2,553,000)			(2,553,000)
Treasury stock acquired — share repurchase authorizations					(500,000)
Net shares acquired related to employee share-based compensation plans					0
Balance, end of period at Jun. 30, 2022	22,874,000	24,419,000	42,684,000	(5,155,000)	(39,074,000)
Balance, beginning of period (in shares) at Mar. 31, 2022						240.0
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)						(2.9)
Net shares issued under employee share-based compensation plans (in shares)						0.2
Balance, end of period (in shares) at Jun. 30, 2022						237.3
Balance, beginning of period at Dec. 31, 2022	21,560,000	24,565,000	43,516,000	(6,445,000)	(40,076,000)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		94,000
Compensation amortization under share-based plans and other changes		117,000
Net income (loss)	961,000		961,000
Dividends			(451,000)
Other			0
Other comprehensive income (loss)	436,000			436,000
Treasury stock acquired — share repurchase authorizations	(800,000)				(800,000)
Net shares acquired related to employee share-based compensation plans	(62,000)				(62,000)
Balance, end of period at Jun. 30, 2023	$ 21,855,000	24,776,000	44,026,000	(6,009,000)	(40,938,000)
Balance, beginning of period (in shares) at Dec. 31, 2022	232.1					232.1
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)	(4.4)					(4.4)
Net shares issued under employee share-based compensation plans (in shares)						1.2
Balance, end of period (in shares) at Jun. 30, 2023	228.9					228.9
Balance, beginning of period at Mar. 31, 2023		24,703,000	44,273,000	(5,386,000)	(40,538,000)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		26,000
Compensation amortization under share-based plans and other changes		47,000
Net income (loss)	$ (14,000)		(14,000)
Dividends			(233,000)
Other			0
Other comprehensive income (loss)	(623,000)			(623,000)
Treasury stock acquired — share repurchase authorizations	(400,000)				(400,000)
Net shares acquired related to employee share-based compensation plans	(146)				0
Balance, end of period at Jun. 30, 2023	$ 21,855,000	$ 24,776,000	$ 44,026,000	$ (6,009,000)	$ (40,938,000)
Balance, beginning of period (in shares) at Mar. 31, 2023						231.0
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)	(2.2)					(2.2)
Net shares issued under employee share-based compensation plans (in shares)						0.1
Balance, end of period (in shares) at Jun. 30, 2023	228.9					228.9