Common Stock/Partners' Capital - Additional Information (Detail) $ / shares in Units, $ in Thousands				1 Months Ended	3 Months Ended	9 Months Ended
	Aug. 11, 2015 USD ($) shares	Jan. 14, 2015 USD ($) shares	Mar. 11, 2014 USD ($) shares	Jan. 31, 2014 USD ($)	Mar. 31, 2014 USD ($) $ / shares shares	Sep. 30, 2015 USD ($) Director Employee Partner $ / shares shares	Sep. 30, 2014 USD ($) shares	Aug. 04, 2015 $ / shares shares	Jun. 30, 2015 $ / shares shares	Dec. 31, 2014 $ / shares shares
Class of Stock [Line Items]
Common stock, shares issued | shares						236,656,000				172,743,000
Proceeds from sale of common shares / units, net of offering costs						$ 817,533	$ 128,270
Common stock, shares authorized | shares						500,000,000		500,000,000	250,000,000	500,000,000
Common stock, par value | $ / shares						$ 0.001		$ 0.001	$ 0.001	$ 0.001
MPT Operating Partnership, L.P. [Member]
Class of Stock [Line Items]
Proceeds from sale of common shares / units, net of offering costs						$ 817,533	$ 128,270
Ownership interest in equity						99.86%
Number of units sold | shares						63,250,000	9,800,000
Number of other partners | Partner						3
Market Equity Offering Program [Member]
Class of Stock [Line Items]
Common stock, shares issued | shares					900,000
Proceeds from sale of common shares / units, net of offering costs					$ 12,300
Sales commission percentage				1.25%
Market Equity Offering Program [Member] | IPO [Member]
Class of Stock [Line Items]
Public offering price for common stock per share | $ / shares					$ 13.21
Market Equity Offering Program [Member] | Maximum [Member]
Class of Stock [Line Items]
Number of shares can be sold out				$ 250,000
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
Public Offering [Member]
Class of Stock [Line Items]
Common stock, shares issued | shares	28,750,000	34,500,000	7,700,000
Proceeds from sale of common shares / units, net of offering costs	$ 337,000	$ 480,000	$ 100,200
Additional shares purchased by underwriters | shares		4,500,000	1,200,000
Time granted to underwriters to purchase shares						30 days
Net proceeds from additional issuance of shares			$ 16,000