Operating Segment Information and Concentrations of Risk - Summary of Gross Sales by Major Customers (Detail) - Customer A [Member] - North America Fiber Cement [Member] - Sales [Member] - Customer Concentration Risk [Member] - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Mar. 31, 2016 |
|
| Segment Reporting Information [Line Items] | |||
| Net sales | $ 246.9 | $ 226.0 | $ 197.0 |
| Gross sales percentage (as percent) | 12.00% | 10.30% | 10.10% |
| X | ||||||||||
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|