Earnings Per Share - Calculation of Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 131,357	$ 109,652	$ 81,157	$ 90,267	$ 79,920	$ 76,291	$ 322,166	$ 246,478
Non-controlling interests’ share in net income	(251)			(481)			(600)	(1,432)
Participating securities’ share in earnings	(435)			(432)			(1,386)	(1,354)
Net income, less participating securities’ share in earnings	$ 130,671			$ 89,354			$ 320,180	$ 243,692
Basic weighted-average common shares	531,095			439,581			526,651	404,902
Dilutive potential common shares	1,341			1,352			1,181	1,198
Dilutive weighted-average common shares	532,436			440,933			527,832	406,100
MPT Operating Partnership, L.P. [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 131,357	$ 109,652	$ 81,157	$ 90,267	$ 79,920	$ 76,291	$ 322,166	$ 246,478
Non-controlling interests’ share in net income	(251)			(481)			(600)	(1,432)
Participating securities’ share in earnings	(435)			(432)			(1,386)	(1,354)
Net income, less participating securities’ share in earnings	$ 130,671			$ 89,354			$ 320,180	$ 243,692
Basic weighted-average common shares	531,095			439,581			526,651	404,902
Dilutive potential common shares	1,341			1,352			1,181	1,198
Dilutive weighted-average common shares	532,436			440,933			527,832	406,100