Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands | Common Stock [Member] Common Class A [Member] | Common Stock [Member] Common Class B [Member] | Common Stock [Member] | Additional Paid-in Capital [Member] | Treasury Stock, Common [Member] | Retained Earnings [Member] Common Class A [Member] | Retained Earnings [Member] Common Class B [Member] | Retained Earnings [Member] | AOCI Attributable to Parent [Member] | Parent [Member] Common Class A [Member] | Parent [Member] Common Class B [Member] | Parent [Member] | Noncontrolling Interest [Member] | Common Class A [Member] | Common Class B [Member] | Total |
Balance (in shares) at Dec. 31, 2021 | 64,662 | 18,598 | | | | | | | | | | | | | | |
Balance at Dec. 31, 2021 | | | $ 563 | $ 470,750 | $ (36,933) | | | $ 1,031,582 | $ 787 | | | $ 1,466,749 | | | | $ 1,466,749 |
Stock options exercised and stock awards (in shares) | 168 | | | | | | | | | | | | | | | |
Stock options exercised and stock awards | | | 1 | 2,384 | | | | | | | | 2,385 | | | | 2,385 |
Stock-based compensation related to stock options, restricted shares and employee stock purchase plan | | | | 13,793 | | | | | | | | 13,793 | | | | |
Vesting of restricted share awards (in shares) | | 454 | | | | | | | | | | | | | | |
Vesting of restricted share awards | | | 3 | (7,215) | | | | | | | | (7,212) | | | | (7,212) |
Issuance of common stock under employee stock purchase plan (in shares) | 99 | | | | | | | | | | | | | | | |
Issuance of common stock under employee stock purchase plan | | | 1 | 2,434 | | | | | | | | 2,435 | | | | 2,435 |
Common stock repurchases (in shares) | (288) | (157) | | | | | | | | | | | | | | |
Common stock repurchases | | | | | (15,315) | | | | | | | (15,315) | | | | (15,315) |
Cash dividends declared | | | | | | $ (8,189) | $ (2,505) | | | $ (8,189) | $ (2,505) | | | | | |
Foreign currency translation | | | | | | | | | 445 | | | 445 | | | | |
Net income | | | | | | | | 92,453 | | | | 92,453 | | | | |
Balance (in shares) at Mar. 31, 2022 | 64,641 | 18,895 | | | | | | | | | | | | | | |
Balance at Mar. 31, 2022 | | | 568 | 482,146 | (52,248) | | | 1,113,341 | 1,232 | | | 1,545,039 | | | | 1,545,039 |
Balance (in shares) at Dec. 31, 2021 | 64,662 | 18,598 | | | | | | | | | | | | | | |
Balance at Dec. 31, 2021 | | | 563 | 470,750 | (36,933) | | | 1,031,582 | 787 | | | 1,466,749 | | | | 1,466,749 |
Foreign currency translation | | | | | | | | | | | | | | | | (5,823) |
Net income | | | | | | | | | | | | | | | | 293,789 |
Balance (in shares) at Sep. 30, 2022 | 63,561 | 18,138 | | | | | | | | | | | | | | |
Balance at Sep. 30, 2022 | | | 571 | 494,703 | (123,781) | | | 1,291,602 | (5,637) | | | 1,657,458 | $ 18,561 | | | 1,676,019 |
Balance (in shares) at Mar. 31, 2022 | 64,641 | 18,895 | | | | | | | | | | | | | | |
Balance at Mar. 31, 2022 | | | 568 | 482,146 | (52,248) | | | 1,113,341 | 1,232 | | | 1,545,039 | | | | 1,545,039 |
Stock options exercised and stock awards (in shares) | 244 | | | | | | | | | | | | | | | |
Stock options exercised and stock awards | | | 2 | 3,244 | | | | | | | | 3,246 | | | | 3,246 |
Stock-based compensation related to stock options, restricted shares and employee stock purchase plan | | | | 4,203 | | | | | | | | 4,203 | | | | 4,203 |
Vesting of restricted share awards | | | | (1,423) | | | | | | | | (1,423) | | | | (1,423) |
Common stock repurchases (in shares) | (673) | (496) | | | | | | | | | | | | | | |
Common stock repurchases | | | | | (38,438) | | | | | | | (38,438) | | | | (38,438) |
Cash dividends declared | | | | | | (8,128) | (2,521) | | | (8,128) | (2,521) | | | $ (8,128) | $ (2,521) | |
Foreign currency translation | | | | | | | | | (567) | | | (567) | | | | (567) |
Net income | | | | | | | | 110,227 | | | | 110,227 | 446 | | | 110,673 |
Balance (in shares) at Jun. 30, 2022 | 64,212 | 18,399 | | | | | | | | | | | | | | |
Balance at Jun. 30, 2022 | | | 570 | 488,170 | (90,686) | | | 1,212,919 | 64 | | | 1,611,037 | 18,274 | | | 1,629,311 |
Reclassification of foreign currency translation related to equity method | | | | | | | | | (601) | | | (601) | | | | (601) |
Noncontrolling interest equity | | | | | | | | | | | | | 17,828 | | | 17,828 |
Stock options exercised and stock awards (in shares) | 16 | | | | | | | | | | | | | | | |
Stock options exercised and stock awards | | | | 227 | | | | | | | | 227 | | | | 227 |
Stock-based compensation related to stock options, restricted shares and employee stock purchase plan | | | | 3,554 | | | | | | | | 3,554 | | | | 3,554 |
Vesting of restricted share awards (in shares) | | 3 | | | | | | | | | | | | | | |
Vesting of restricted share awards | | | | (31) | | | | | | | | (31) | | | | (31) |
Issuance of common stock under employee stock purchase plan (in shares) | 102 | | | | | | | | | | | | | | | |
Issuance of common stock under employee stock purchase plan | | | 1 | 2,783 | | | | | | | | 2,784 | | | | 2,784 |
Common stock repurchases (in shares) | (769) | (264) | | | | | | | | | | | | | | |
Common stock repurchases | | | | | (33,095) | | | | | | | (33,095) | | | | (33,095) |
Cash dividends declared | | | | | | (8,995) | (2,698) | | | (8,995) | (2,698) | | | (8,995) | (2,698) | |
Foreign currency translation | | | | | | | | | (5,701) | | | (5,701) | | | | (5,701) |
Net income | | | | | | | | 90,376 | | | | 90,376 | 287 | | | 90,663 |
Balance (in shares) at Sep. 30, 2022 | 63,561 | 18,138 | | | | | | | | | | | | | | |
Balance at Sep. 30, 2022 | | | 571 | 494,703 | (123,781) | | | 1,291,602 | (5,637) | | | 1,657,458 | 18,561 | | | 1,676,019 |
Balance (in shares) at Dec. 31, 2022 | 63,518 | 18,125 | | | | | | | | | | | | | | |
Balance at Dec. 31, 2022 | | | 572 | 500,642 | (130,930) | | | 1,378,337 | (4,130) | | | 1,744,491 | | | | 1,763,022 |
Stock options exercised and stock awards (in shares) | 228 | | | | | | | | | | | | | | | |
Stock options exercised and stock awards | | | 2 | 3,412 | | | | | | | | 3,414 | | | | 3,414 |
Stock-based compensation related to stock options, restricted shares and employee stock purchase plan | | | | 13,080 | | | | | | | | 13,080 | | | | 13,080 |
Vesting of restricted share awards (in shares) | | 422 | | | | | | | | | | | | | | |
Vesting of restricted share awards | | | 3 | (6,964) | | | | | | | | (6,961) | | | | (6,961) |
Issuance of common stock under employee stock purchase plan (in shares) | 102 | | | | | | | | | | | | | | | |
Issuance of common stock under employee stock purchase plan | | | | 2,828 | | | | | | | | 2,828 | | | | 2,828 |
Common stock repurchases (in shares) | (623) | (84) | | | | | | | | | | | | | | |
Common stock repurchases | | | | | (25,280) | | | | | | | (25,280) | | | | (25,280) |
Cash dividends declared | | | | | | (8,897) | (2,692) | | | (8,897) | (2,692) | | | (8,897) | (2,692) | |
Foreign currency translation | | | | | | | | | 232 | | | 232 | | | | 232 |
Net income | | | | | | | | 90,455 | | | | 90,455 | 335 | | | 90,790 |
Balance (in shares) at Mar. 31, 2023 | 63,225 | 18,463 | | | | | | | | | | | | | | |
Balance at Mar. 31, 2023 | | | 577 | 512,998 | (156,210) | | | 1,457,203 | (3,898) | | | 1,810,670 | 18,866 | | | 1,829,536 |
Balance (in shares) at Dec. 31, 2022 | 63,518 | 18,125 | | | | | | | | | | | | | | |
Balance at Dec. 31, 2022 | | | 572 | 500,642 | (130,930) | | | 1,378,337 | (4,130) | | | 1,744,491 | | | | 1,763,022 |
Foreign currency translation | | | | | | | | | | | | | | | | (187) |
Net income | | | | | | | | | | | | | | | | 269,948 |
Balance (in shares) at Sep. 30, 2023 | 62,053 | 17,989 | | | | | | | | | | | | | | |
Balance at Sep. 30, 2023 | | | 804 | 533,648 | (16,169) | | | 1,385,646 | (4,317) | | | 1,899,612 | 19,471 | | | 1,919,083 |
Balance (in shares) at Mar. 31, 2023 | 63,225 | 18,463 | | | | | | | | | | | | | | |
Balance at Mar. 31, 2023 | | | 577 | 512,998 | (156,210) | | | 1,457,203 | (3,898) | | | 1,810,670 | 18,866 | | | 1,829,536 |
Stock options exercised and stock awards (in shares) | 237 | | | | | | | | | | | | | | | |
Stock options exercised and stock awards | | | 1 | 3,479 | | | | | | | | 3,480 | | | | 3,480 |
Stock-based compensation related to stock options, restricted shares and employee stock purchase plan | | | | 5,952 | | | | | | | | 5,952 | | | | 5,952 |
Vesting of restricted share awards | | | | (54) | | | | | | | | (54) | | | | (54) |
Common stock repurchases (in shares) | (890) | (195) | | | | | | | | | | | | | | |
Common stock repurchases | | | | | (40,305) | | | | | | | (40,305) | | | | (40,305) |
Cash dividends declared | | | | | | (8,812) | (2,725) | | | (8,812) | (2,725) | | | (8,812) | (2,725) | |
Foreign currency translation | | | | | | | | | 1,689 | | | 1,689 | | | | 1,689 |
Net income | | | | | | | | 98,275 | | | | 98,275 | 249 | | | 98,524 |
Balance (in shares) at Jun. 30, 2023 | 62,572 | 18,268 | | | | | | | | | | | | | | |
Balance at Jun. 30, 2023 | | | 578 | 522,375 | (196,515) | | | 1,543,941 | (2,209) | | | 1,868,170 | 19,115 | | | 1,887,285 |
Stock options exercised and stock awards (in shares) | 124 | | | | | | | | | | | | | | | |
Stock options exercised and stock awards | | | 1 | 1,888 | | | | | | | | 1,889 | | | | 1,889 |
Stock-based compensation related to stock options, restricted shares and employee stock purchase plan | | | | 6,265 | | | | | | | | 6,265 | | | | 6,265 |
Issuance of common stock under employee stock purchase plan (in shares) | 107 | | | | | | | | | | | | | | | |
Issuance of common stock under employee stock purchase plan | | | 1 | 3,123 | | | | | | | | 3,124 | | | | 3,124 |
Common stock repurchases (in shares) | (750) | (279) | | | | | | | | | | | | | | |
Common stock repurchases | | | | | (44,174) | | | | | | | (44,174) | | | | (44,174) |
Cash dividends declared | | | | | | $ (10,574) | $ (3,255) | | | $ (10,574) | $ (3,255) | | | $ (10,574) | $ (3,255) | |
Foreign currency translation | | | | | | | | | (2,108) | | | (2,108) | | | | (2,108) |
Net income | | | | | | | | 80,278 | | | | 80,278 | 356 | | | 80,634 |
Balance (in shares) at Sep. 30, 2023 | 62,053 | 17,989 | | | | | | | | | | | | | | |
Balance at Sep. 30, 2023 | | | 804 | 533,648 | (16,169) | | | 1,385,646 | $ (4,317) | | | 1,899,612 | $ 19,471 | | | 1,919,083 |
Retirement of treasury shares and par value adjustment | | | 224 | 3 | (224,520) | | | 224,744 | | | | 3 | | | | 3 |
Retirement of treasury shares and par value adjustment | | | $ (224) | $ (3) | $ 224,520 | | | $ (224,744) | | | | $ (3) | | | | $ (3) |