v3.19.3.a.u2
Cover
Feb. 04, 2020
Cover page.  
Document Type 8-K
Document Period End Date Feb. 04, 2020
Entity Registrant Name MGIC Investment Corporation
Entity Incorporation, State or Country Code WI
Entity File Number 1-10816
Entity Tax Identification Number 39-1486475
Entity Address, Address Line One 250 E. Kilbourn Avenue
Entity Address, City or Town Milwaukee,
Entity Address, State or Province WI
Entity Address, Postal Zip Code 53202
City Area Code  (414)
Local Phone Number 347-6480
Title of each class Common stock
Trading Symbol MTG
Security Exchange Name NYSE
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company false
Entity Central Index Key 0000876437
Amendment Flag false