Nature of Business and Significant Accounting Policies (Details Textual) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ (164,643)	$ (123,732)
Gains and (losses) netted against other income, net	(2,200)	(2,500)	$ 200
Other Inventory, Demo, Gross	36,900	36,800
Advertising costs	19,300	18,700	$ 12,600
Carrying value of cost-basis investments	$ 3,200	$ 5,200
Effect of stock-based compensation awards, shares excluded for purposes of diluted earnings per share	233	354	171
Unrecognized stock-based compensation costs, net of estimated forfeitures	$ 41,000
Weighted average period of unrecognized stock-based compensation costs, net of estimated forfeitures	1 year 10 months 24 days
Estimated forfeiture rate	5.00%
Level 1
Cash equivalents at fair value	$ 8,300	$ 29,000
Time-vested restricted stock unit
Restricted stock units granted	865	804	685
Time-vested and performance-based restricted stock unit
Weighted average grant date fair value per share	$ 29.48	$ 26.30	$ 32.80
Market-based restricted stock unit
Total fair value of awards granted	$ 1,500
Performance-based restricted stock unit [Domain]
Total fair value of awards granted	1,600
Restricted Stock Unit Awards
Total fair value of awards granted	$ 28,603	$ 27,150	$ 22,484
Market-based restricted stock unit
Restricted stock units granted	64	128
Weighted average grant date fair value per share	$ 22.89	$ 25.55
Stock Option Awards
Cash received from the exercise of stock options	$ 7,700	$ 20,800	44,200
Related tax benefit realized from the exercise of the stock options	$ 1,300	$ 3,900	$ 12,800