Label	Element	Value
Effect of Change in Accounting Principle	mos_EffectofChangeinAccountingPrinciple	$ 600,000
Restricted Cash Equivalents, Current	us-gaap_RestrictedCashEquivalentsCurrent	8,200,000
Restricted Cash Equivalents, Current	us-gaap_RestrictedCashEquivalentsCurrent	8,600,000
Retained Earnings [Member]
Effect of Change in Accounting Principle	mos_EffectofChangeinAccountingPrinciple	$ 600,000

Amount of cash equivalents restricted as to withdrawal or usage, classified as current. Cash equivalents include, but are not limited to, 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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e6676-107765

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=121583591&loc=SL98516268-108586

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_RestrictedCashEquivalentsCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant