Acquisitions (Details)	Dec. 31, 2017 store
Business Acquisition [Line Items]
Number of sales centers	351
Lincoln Equipment, Inc. (Lincoln Aquatics) [Member]
Business Acquisition [Line Items]
Number of sales centers	1
New Star Holdings Pty. Ltd. [Member]
Business Acquisition [Line Items]
Number of sales centers	1
E-Grupa [Member]
Business Acquisition [Line Items]
Number of sales centers	1
Kripsol Intermark Malaga S.L. (Intermark) [Member]
Business Acquisition [Line Items]
Number of sales centers	1
Chem Quip, Inc. [Member]
Business Acquisition [Line Items]
Number of sales centers	5
Metro Irrigation Supply Company Ltd. [Member]
Business Acquisition [Line Items]
Number of sales centers	8
PoolwerxDevelopmentLLC [Member]
Business Acquisition [Line Items]
Number of sales centers	1
Seaboard Industries Inc [Member]
Business Acquisition [Line Items]
Number of sales centers	3
The Melton Corporation [Member]
Business Acquisition [Line Items]
Number of sales centers	2