Organization and Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Business Acquisition [Line Items]
Number of sales centers in North America, Europe, South America and Australia	351
Number of distribution networks	4
Shipping and handling costs associated with outbound freight	$ 45,247,000	$ 39,879,000	$ 36,783,000
Advertising expense	7,477,000	7,011,000	7,127,000
Gains (losses) on foreign currency transactions	171,000	(679,000)	(774,000)
Threshold past due account balances for reserve analysis	$ 20,000
Threshold past due days for reserve analysis	60 days
Sales period (in months) for establishing reserve for inventory obsolescence	12 months
Depreciation expense	$ 24,157,000	20,338,000	16,373,000
Cumulative Share Repurchases	1,239,297,000
Cumulative Dividends	$ 425,777,000
Controlling interest by parent	60.00%
Cash paid during the year for [Abstract]
Interest	$ 12,957,000	8,052,000	6,316,000
Income taxes, net of refunds	$ 84,251,000	$ 80,378,000	$ 65,668,000