CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
CONSOLIDATED BALANCE SHEETS
Amortized Cost	$ 5,025,433	$ 4,080,663
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	300,000,000	300,000,000
Common stock, issued (in shares)	140,140,542	139,917,150
Common stock outstanding (in shares)	129,866,898	129,928,479
Treasury stock (in shares)	10,273,644	9,988,671

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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