Common Stock/Partners' Capital - Additional Information (Detail) shares in Thousands, $ in Thousands		6 Months Ended
	May 01, 2017 USD ($) shares	Jun. 30, 2017 USD ($) Partner Director Employee shares	Jun. 30, 2016 USD ($) shares	Dec. 31, 2016 shares
Class of Stock [Line Items]
Common stock, shares issued | shares		364,020		320,514
Proceeds from sale of common shares / units, net of offering costs | $		$ 548,063	$ 44,306
Public Offering [Member]
Class of Stock [Line Items]
Common stock, shares issued | shares	43,100
Additional shares purchased by underwriters | shares	5,600
Proceeds from sale of common shares / units, net of offering costs | $	$ 548,000
MPT Operating Partnership, L.P. [Member]
Class of Stock [Line Items]
Proceeds from sale of common shares / units, net of offering costs | $		$ 548,063	$ 44,306
Number of units sold | shares		43,100	3,000
MPT Operating Partnership, L.P. [Member]
Class of Stock [Line Items]
Ownership interest in equity		99.89%
Number of other partners | Partner		3
Employee [Member]
Class of Stock [Line Items]
Number of partners shared remaining ownership percentage | Employee		2
Director [Member]
Class of Stock [Line Items]
Number of partners shared remaining ownership percentage | Director		1
Market Equity Offering Program [Member]
Class of Stock [Line Items]
Common stock, shares issued | shares			3,000
Proceeds from sale of common shares / units, net of offering costs | $			$ 45,000
Sales commissions, amount | $			$ 600