Document And Entity Information	9 Months Ended
	Sep. 30, 2012	Oct. 22, 2012 Capital Stock [Member]	Oct. 22, 2012 Class B Capital Stock [Member]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2012
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2012
Entity Registrant Name	MONARCH CEMENT CO
Entity Central Index Key	0000067517
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		2,583,709	1,429,925
Trading Symbol	mcem