Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands | Total | Common Stock | Additional Paid-in Capital | Retained Earnings | Accumulated Other Comprehensive Loss |
Beginning Balance (in shares) at Dec. 31, 2017 | | 37,729 | | | |
Beginning Balance at Dec. 31, 2017 | $ 1,191,971 | $ 377 | $ 266,035 | $ 1,045,774 | $ (120,215) |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | |
Net income | 38,945 | | | 38,945 | |
Other comprehensive loss: | | | | | |
Cumulative translation adjustment | 10,446 | | | | 10,446 |
Issuance of common stock in connection with: | | | | | |
Exercise of options (in shares) | | 153 | | | |
Exercise of options | 5,794 | $ 1 | 5,793 | | |
Restricted share grants, less net settled shares (in shares) | | 175 | | | |
Restricted share grants, less net settled shares | (1,579) | $ 2 | (1,581) | | |
Stock units issued under incentive compensation plan | 1,059 | | 1,059 | | |
Purchase and retirement of common stock (in shares) | | (337) | | | |
Purchase and retirement of common stock | (14,220) | $ (3) | (14,217) | | |
Share-based compensation | 4,676 | | 4,676 | | |
Ending Balance (in shares) at Mar. 31, 2018 | | 37,720 | | | |
Ending Balance at Mar. 31, 2018 | 1,237,434 | $ 377 | 261,765 | 1,085,061 | (109,769) |
Beginning Balance (in shares) at Dec. 31, 2017 | | 37,729 | | | |
Beginning Balance at Dec. 31, 2017 | 1,191,971 | $ 377 | 266,035 | 1,045,774 | (120,215) |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | |
Net income | 126,887 | | | | |
Other comprehensive loss: | | | | | |
Cumulative translation adjustment | (17,417) | | | | |
Issuance of common stock in connection with: | | | | | |
Stock units issued under incentive compensation plan | 1,059 | | | | |
Ending Balance (in shares) at Sep. 30, 2018 | | 38,356 | | | |
Ending Balance at Sep. 30, 2018 | 1,351,475 | $ 384 | 315,720 | 1,173,003 | (137,632) |
Beginning Balance (in shares) at Mar. 31, 2018 | | 37,720 | | | |
Beginning Balance at Mar. 31, 2018 | 1,237,434 | $ 377 | 261,765 | 1,085,061 | (109,769) |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | |
Net income | 43,609 | | | 43,609 | |
Other comprehensive loss: | | | | | |
Cumulative translation adjustment | (23,683) | | | | (23,683) |
Issuance of common stock in connection with: | | | | | |
Exercise of options (in shares) | | 360 | | | |
Exercise of options | 14,806 | $ 4 | 14,802 | | |
Restricted share grants, less net settled shares (in shares) | | 99 | | | |
Restricted share grants, less net settled shares | (252) | $ 1 | (253) | | |
Share-based compensation | 3,887 | | 3,887 | | |
Ending Balance (in shares) at Jun. 30, 2018 | | 38,179 | | | |
Ending Balance at Jun. 30, 2018 | 1,275,801 | $ 382 | 280,201 | 1,128,670 | (133,452) |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | |
Net income | 44,333 | | | 44,333 | |
Other comprehensive loss: | | | | | |
Cumulative translation adjustment | (4,180) | | | | (4,180) |
Issuance of common stock in connection with: | | | | | |
Exercise of options (in shares) | | 340 | | | |
Exercise of options | 13,569 | $ 4 | 13,565 | | |
Restricted share grants, less net settled shares (in shares) | | 33 | | | |
Restricted share grants, less net settled shares | (835) | $ 0 | (835) | | |
Purchase and retirement of common stock (in shares) | | (196) | | | |
Purchase and retirement of common stock | (15,000) | $ (2) | (14,998) | | |
Conversion feature of convertible senior notes due 2023, net | 34,131 | | 34,131 | | |
Share-based compensation | 3,656 | | 3,656 | | |
Ending Balance (in shares) at Sep. 30, 2018 | | 38,356 | | | |
Ending Balance at Sep. 30, 2018 | $ 1,351,475 | $ 384 | 315,720 | 1,173,003 | (137,632) |
Beginning Balance (in shares) at Dec. 31, 2018 | 38,147 | 38,147 | | | |
Beginning Balance at Dec. 31, 2018 | $ 1,348,825 | $ 381 | 299,534 | 1,196,727 | (147,817) |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | |
Net income | 62,645 | | | 62,645 | |
Other comprehensive loss: | | | | | |
Cumulative translation adjustment | 5,223 | | | | 5,223 |
Issuance of common stock in connection with: | | | | | |
Exercise of options (in shares) | | 55 | | | |
Exercise of options | 2,212 | $ 1 | 2,211 | | |
Restricted share grants, less net settled shares (in shares) | | 153 | | | |
Restricted share grants, less net settled shares | (2,739) | $ 1 | (2,740) | | |
Stock units issued under incentive compensation plan | 1,346 | | 1,346 | | |
Purchase and retirement of common stock (in shares) | | (328) | | | |
Purchase and retirement of common stock | (21,883) | $ (3) | (21,880) | | |
Share-based compensation | 6,393 | | 6,393 | | |
Ending Balance (in shares) at Mar. 31, 2019 | | 38,027 | | | |
Ending Balance at Mar. 31, 2019 | $ 1,402,022 | $ 380 | 284,864 | 1,259,372 | (142,594) |
Beginning Balance (in shares) at Dec. 31, 2018 | 38,147 | 38,147 | | | |
Beginning Balance at Dec. 31, 2018 | $ 1,348,825 | $ 381 | 299,534 | 1,196,727 | (147,817) |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | |
Net income | 187,665 | | | | |
Other comprehensive loss: | | | | | |
Cumulative translation adjustment | (16,225) | | | | |
Issuance of common stock in connection with: | | | | | |
Stock units issued under incentive compensation plan | $ 1,413 | | | | |
Ending Balance (in shares) at Sep. 30, 2019 | 37,629 | 37,629 | | | |
Ending Balance at Sep. 30, 2019 | $ 1,461,234 | $ 376 | 240,508 | 1,384,392 | (164,042) |
Beginning Balance (in shares) at Mar. 31, 2019 | | 38,027 | | | |
Beginning Balance at Mar. 31, 2019 | 1,402,022 | $ 380 | 284,864 | 1,259,372 | (142,594) |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | |
Net income | 64,598 | | | 64,598 | |
Other comprehensive loss: | | | | | |
Cumulative translation adjustment | (4,815) | | | | (4,815) |
Issuance of common stock in connection with: | | | | | |
Exercise of options (in shares) | | 87 | | | |
Exercise of options | 3,076 | $ 1 | 3,075 | | |
Restricted share grants, less net settled shares (in shares) | | 78 | | | |
Restricted share grants, less net settled shares | (1,351) | $ 1 | (1,352) | | |
Purchase and retirement of common stock (in shares) | | (580) | | | |
Purchase and retirement of common stock | (48,332) | $ (6) | (48,326) | | |
Share-based compensation | 3,814 | | 3,814 | | |
Ending Balance (in shares) at Jun. 30, 2019 | | 37,612 | | | |
Ending Balance at Jun. 30, 2019 | 1,419,012 | $ 376 | 242,075 | 1,323,970 | (147,409) |
Increase (Decrease) in Stockholders' Equity [Roll Forward] | | | | | |
Net income | 60,422 | | | 60,422 | |
Other comprehensive loss: | | | | | |
Cumulative translation adjustment | (16,633) | | | | (16,633) |
Issuance of common stock in connection with: | | | | | |
Exercise of options (in shares) | | 94 | | | |
Exercise of options | 3,569 | $ 1 | 3,568 | | |
Restricted share grants, less net settled shares (in shares) | | 14 | | | |
Restricted share grants, less net settled shares | (1,322) | $ 0 | (1,322) | | |
Stock units issued under incentive compensation plan | 67 | | 67 | | |
Purchase and retirement of common stock (in shares) | | (91) | | | |
Purchase and retirement of common stock | (7,734) | $ (1) | (7,733) | | |
Share-based compensation | $ 3,853 | | 3,853 | | |
Ending Balance (in shares) at Sep. 30, 2019 | 37,629 | 37,629 | | | |
Ending Balance at Sep. 30, 2019 | $ 1,461,234 | $ 376 | $ 240,508 | $ 1,384,392 | $ (164,042) |