Shareholders' Equity (Narrative) (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) vote class $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) vote $ / shares shares	Oct. 25, 2021 USD ($)	Dec. 31, 2020 shares
Class of Stock [Line Items]
Number of classes of common stock | class	1
Stock repurchase program, authorized amount		$ 200,000,000		$ 200,000,000
Treasury stock, common shares (in shares) | shares	9,661,845	9,674,542
Purchase of treasury shares		$ 85,065,000	$ 24,375,000
Maximum
Class of Stock [Line Items]
Authorized to repurchase shares in amount	$ 90,600,000
Treasury Stock, Common
Class of Stock [Line Items]
Treasury stock, common shares (in shares) | shares	9,662,000	9,675,000	8,665,000		8,391,000
Purchase of treasury shares		$ 85,065,000	$ 24,375,000
Purchases of common stock (in shares) | shares		1,022,717	285,286
2021 And 2022 Share Purchases
Class of Stock [Line Items]
Treasury stock, common shares (in shares) | shares	1,308,003
Purchase of treasury shares	$ 109,400,000
Common Class A
Class of Stock [Line Items]
Common stock, par or stated value per share (in dollars per share) | $ / shares	$ 0.001	$ 0.001
Number of votes entitled to shareholders per share of common stock | vote	1
Common Class B
Class of Stock [Line Items]
Common stock, par or stated value per share (in dollars per share) | $ / shares	$ 0.001		$ 0.001
Number of votes entitled to shareholders per share of common stock | vote			10