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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.

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The cash outflow from the repayment of long-term borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in case of liquidation of the entity's assets before its maturity.

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This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

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This element represents the undistributed income (or loss) of equity method investments, net of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporations; such investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities.

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The increase (decrease) during the reporting period in the aggregate amount of liabilities that result from activities that generate operating income.

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Amount of increase (decrease) in operating assets classified as other.

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The increase (decrease) in cash associated with the entity's continuing operating, investing, and financing activities. While for technical reasons this element has no balance attribute, the default assumption is a debit balance consistent with its label.

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Amount of cash inflow (outflow) of financing activities, excluding discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) of investing activities, excluding discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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Amount of cash inflow (outflow) from operating activities, excluding discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

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The cash outflow to acquire debt and equity securities not classified as either held-to-maturity securities or trading securities which would be classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity.

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Amount of noncash expense for share-based payment arrangement.

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Condensed Financial Information Of Parent Company Condensed Financial Information Of Parent Company (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)	$ 116,830	$ 45,503	$ 33,204	$ (1,433,111)	$ 117,881	$ 110,026	$ 128,125	$ 112,604	$ (1,237,574)	$ 468,636	$ 465,339
Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract]
Decrease (increase) in other assets									(105,749)	30,261	24,981
Gain on sale of securities, net									(13,171)	(25,445)	(8,176)
Earned stock compensation									24,363	26,815	29,768
Net Cash Provided by (Used in) Investing Activities [Abstract]
Payments to Acquire Available-for-sale Securities									(1,924,917)	(1,569,421)	(1,180,545)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Restricted stock surrendered									(75,369)	(162,965)	(315,542)
Cash dividends paid, net									(159,748)	(289,048)	(288,193)
Supplemental Cash Flow Information [Abstract]
shares of unvested restricted stock, respectively)	1,207				1,219				1,207	1,219
Net decrease in subordinated debentures										0	(12,372)
Parent Only
Condensed Financial Statements, Captions [Line Items]
Net earnings (loss)									(1,237,574)	468,636	465,339
Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract]
Decrease (increase) in other assets									(29,568)	(35,510)	(36,362)
Increase (Decrease) in Operating Liabilities									780	(1,661)	(953)
Earned stock compensation										26,815	29,768
Income (Loss) from Equity Method Investments, Net of Dividends or Distributions									1,491,004	(137,165)	217,663
Net cash provided by operating activities									249,005	321,115	675,455
Net Cash Provided by (Used in) Investing Activities [Abstract]
Net Cash Provided by (Used in) Investing Activities, Continuing Operations									0	0	0
Net Cash Provided by (Used in) Financing Activities [Abstract]
Restricted stock surrendered										(162,965)	(315,542)
Cash dividends paid, net										(289,048)	(288,193)
Net cash provided by (used in) financing activities									(235,117)	(452,013)	(616,107)
Net Cash Provided by (Used in) Continuing Operations									13,888	(130,898)	59,348
Cash and Cash Equivalents, at Carrying Value	$ 127,849				$ 113,961				127,849	113,961	244,859	$ 185,511
Parent
Supplemental Cash Flow Information [Abstract]
Net decrease in subordinated debentures									$ 0	$ 0	$ (12,372)