CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - UNAUDITED - USD ($) shares in Thousands, $ in Thousands | Total | Common Stock | Common Stock Warrants | Additional Paid-in Capital | Treasury Stock | Accumulated Other Comprehensive Income (Loss) | Accumulated Earnings |
Balance, beginning of period at Dec. 31, 2018 | $ 361,024 | $ 693 | $ 9,082 | $ 441,417 | $ (842,360) | $ (42,935) | $ 795,127 |
Balance, beginning of period, shares at Dec. 31, 2018 | | 33,158 | | | | | |
Net income | | | | | | | 19,251 |
Unrealized gain on short-term investments, net of tax | | | | | | 18 | |
Foreign currency translation adjustments | | | | | | 3,847 | |
Total comprehensive income, net of tax | 23,116 | | | | | | |
Repurchase of common stock | (13,424) | | | (4,134) | (9,290) | | |
Repurchase of common stock, shares | | (352) | | | | | |
Issuance of common stock pursuant to employee stock purchase plan | 512 | | | 512 | | | |
Issuance of common stock pursuant to employee stock purchase plan, shares | | 15 | | | | | |
Issuance of restricted common stock pursuant to stock-based compensation plans | | $ 4 | | (4) | | | |
Issuance of restricted common stock pursuant to stock-based compensation plans, shares | | 462 | | | | | |
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares | | (3) | | | | | |
Stock-based compensation expense | 3,693 | | | 3,693 | | | |
Dividends | (7,411) | | | | | | (7,411) |
Balance, ending of period at Mar. 31, 2019 | 367,510 | $ 697 | 9,082 | 441,484 | (851,650) | (39,070) | 806,967 |
Balance, ending of period, shares at Mar. 31, 2019 | | 33,280 | | | | | |
Balance, beginning of period at Dec. 31, 2018 | 361,024 | $ 693 | 9,082 | 441,417 | (842,360) | (42,935) | 795,127 |
Balance, beginning of period, shares at Dec. 31, 2018 | | 33,158 | | | | | |
Net income | 38,630 | | | | | | |
Unrealized gain on short-term investments, net of tax | 28 | | | | | | |
Foreign currency translation adjustments | 29 | | | | | | |
Total comprehensive income, net of tax | 38,687 | | | | | | |
Balance, ending of period at Jun. 30, 2019 | 374,324 | $ 696 | 9,082 | 446,512 | (858,186) | (42,878) | 819,098 |
Balance, ending of period, shares at Jun. 30, 2019 | | 33,062 | | | | | |
Balance, beginning of period at Mar. 31, 2019 | 367,510 | $ 697 | 9,082 | 441,484 | (851,650) | (39,070) | 806,967 |
Balance, beginning of period, shares at Mar. 31, 2019 | | 33,280 | | | | | |
Net income | 19,379 | | | | | | 19,379 |
Unrealized gain on short-term investments, net of tax | 10 | | | | | 10 | |
Foreign currency translation adjustments | (3,818) | | | | | (3,818) | |
Total comprehensive income, net of tax | 15,571 | | | | | | |
Repurchase of common stock | (6,919) | | | (383) | (6,536) | | |
Repurchase of common stock, shares | | (148) | | | | | |
Issuance of common stock pursuant to employee stock purchase plan | 603 | | | 603 | | | |
Issuance of common stock pursuant to employee stock purchase plan, shares | | 15 | | | | | |
Issuance of restricted common stock pursuant to stock-based compensation plans, shares | | 6 | | | | | |
Cancellation of restricted common stock issued pursuant to stock-based compensation plans | | $ (1) | | 1 | | | |
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares | | (91) | | | | | |
Stock-based compensation expense | 4,807 | | | 4,807 | | | |
Dividends | (7,248) | | | | | | (7,248) |
Balance, ending of period at Jun. 30, 2019 | 374,324 | $ 696 | $ 9,082 | 446,512 | (858,186) | (42,878) | 819,098 |
Balance, ending of period, shares at Jun. 30, 2019 | | 33,062 | | | | | |
Balance, beginning of period at Dec. 31, 2019 | $ 396,662 | $ 696 | | 454,663 | (867,817) | (39,503) | 848,623 |
Balance, beginning of period, shares at Dec. 31, 2019 | 32,891 | 32,891 | | | | | |
Net income | | | | | | | 21,514 |
Unrealized gain on short-term investments, net of tax | | | | | | (24) | |
Foreign currency translation adjustments | | | | | | (15,084) | |
Total comprehensive income, net of tax | $ 6,406 | | | | | | |
Repurchase of common stock | (13,965) | $ (2) | | (7,555) | (6,408) | | |
Repurchase of common stock, shares | | (299) | | | | | |
Issuance of common stock pursuant to employee stock purchase plan | 564 | | | 564 | | | |
Issuance of common stock pursuant to employee stock purchase plan, shares | | 14 | | | | | |
Issuance of restricted common stock pursuant to stock-based compensation plans | | $ 5 | | (5) | | | |
Issuance of restricted common stock pursuant to stock-based compensation plans, shares | | 476 | | | | | |
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares | | (7) | | | | | |
Stock-based compensation expense | 4,857 | | | 4,857 | | | |
Dividends | (7,693) | | | | | | (7,693) |
Balance, ending of period at Mar. 31, 2020 | 386,831 | $ 699 | | 452,524 | (874,225) | (54,611) | 862,444 |
Balance, ending of period, shares at Mar. 31, 2020 | | 33,075 | | | | | |
Balance, beginning of period at Dec. 31, 2019 | $ 396,662 | $ 696 | | 454,663 | (867,817) | (39,503) | 848,623 |
Balance, beginning of period, shares at Dec. 31, 2019 | 32,891 | 32,891 | | | | | |
Net income | $ 31,880 | | | | | | |
Unrealized gain on short-term investments, net of tax | 28 | | | | | | |
Foreign currency translation adjustments | (12,413) | | | | | | |
Total comprehensive income, net of tax | 19,495 | | | | | | |
Balance, ending of period at Jun. 30, 2020 | $ 397,622 | $ 699 | | 458,362 | (874,592) | (51,888) | 865,041 |
Balance, ending of period, shares at Jun. 30, 2020 | 33,080 | 33,080 | | | | | |
Balance, beginning of period at Mar. 31, 2020 | $ 386,831 | $ 699 | | 452,524 | (874,225) | (54,611) | 862,444 |
Balance, beginning of period, shares at Mar. 31, 2020 | | 33,075 | | | | | |
Net income | 10,366 | | | | | | 10,366 |
Unrealized gain on short-term investments, net of tax | 52 | | | | | 52 | |
Foreign currency translation adjustments | 2,671 | | | | | 2,671 | |
Total comprehensive income, net of tax | 13,089 | | | | | | |
Repurchase of common stock | (467) | | | (100) | (367) | | |
Repurchase of common stock, shares | | (11) | | | | | |
Issuance of common stock pursuant to employee stock purchase plan | 683 | | | 683 | | | |
Issuance of common stock pursuant to employee stock purchase plan, shares | | 18 | | | | | |
Issuance of restricted common stock pursuant to stock-based compensation plans, shares | | 12 | | | | | |
Cancellation of restricted common stock issued pursuant to stock-based compensation plans, shares | | (14) | | | | | |
Stock-based compensation expense | 5,255 | | | 5,255 | | | |
Dividends | (7,769) | | | | | | (7,769) |
Balance, ending of period at Jun. 30, 2020 | $ 397,622 | $ 699 | | $ 458,362 | $ (874,592) | $ (51,888) | $ 865,041 |
Balance, ending of period, shares at Jun. 30, 2020 | 33,080 | 33,080 | | | | | |