XML 76 R10.htm IDEA: XBRL DOCUMENT
v3.20.1

Cash and Cash Equivalents, Restricted Cash and Restricted Cash - Asbestos Cash and Cash Equivalents, Restricted Cash and Restricted Cash - Asbestos (Notes) | 12 Months Ended
--- | ---
Mar. 31, 2020
Cash and Cash Equivalents, Restricted Cash and Restricted Cash - Asbestos [Abstract] |
Cash and Cash Equivalents Disclosure [Text Block] | Cash and Cash Equivalents, Restricted Cash and Restricted Cash - Asbestos The following table provides a reconciliation of Cash and cash equivalents, Restricted cash and Restricted cash - Asbestos reported within the consolidated balance sheets that sum to the total of the same such amounts shown in the consolidated statements of cash flows:
| 31 March
(Millions of US dollars) | 2020 |  | 2019 |  | 2018 |  | 2017
Cash and cash equivalents | $ | 144.4 |  |  | $ | 78.7 |  |  | $ | 281.6 |  |  | $ | 78.9 |
Restricted cash | 5.0 |  |  | 5.1 |  |  | 5.0 |  |  | 5.0 |
Restricted cash - Asbestos | 36.4 |  |  | 39.8 |  |  | 26.6 |  |  | 108.9 |
Total cash and cash equivalents, restricted cash and restricted cash - Asbestos | $ | 185.8 |  |  | $ | 123.6 |  |  | $ | 313.2 |  |  | $ | 192.8 |
Restricted cash relates to an insurance policy which restricts the cash from general corporate purposes. Restricted cash - Asbestos is restricted to the settlement of asbestos claims and for the payment of the operating costs of AICF.

X
- Definition Cash and Cash Equivalents, Restricted Cash and Restricted Cash - Asbestos [Abstract] + References No definition available. + Details
Name: | jhx_CashandCashEquivalentsRestrictedCashandRestrictedCashAsbestosAbstract
Namespace Prefix: | jhx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for cash and cash equivalent footnotes, which may include the types of deposits and money market instruments, applicable carrying amounts, restricted amounts and compensating balance arrangements. Cash and equivalents include: (1) currency on hand (2) demand deposits with banks or financial institutions (3) other kinds of accounts that have the general characteristics of demand deposits (4) short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments maturing within three months from the date of acquisition qualify. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 305 -URI http://asc.fasb.org/topic&trid=2122426 + Details
Name: | us-gaap_CashAndCashEquivalentsDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration