Earnings Per Share - Calculation of Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 109,652	$ 81,157	$ 79,920	$ 76,291	$ 190,809	$ 156,211
Non-controlling interests’ share in net income	(184)		(482)		(349)	(951)
Participating securities’ share in earnings	(487)		(446)		(951)	(922)
Net income, less participating securities’ share in earnings	$ 108,981		$ 78,992		$ 189,509	$ 154,338
Basic weighted-average common shares	527,781		394,574		524,428	387,563
Dilutive potential common shares	1,099		1,118		1,102	1,120
Dilutive weighted-average common shares	528,880		395,692		525,530	388,683
MPT Operating Partnership, L.P. [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 109,652	$ 81,157	$ 79,920	$ 76,291	$ 190,809	$ 156,211
Non-controlling interests’ share in net income	(184)		(482)		(349)	(951)
Participating securities’ share in earnings	(487)		(446)		(951)	(922)
Net income, less participating securities’ share in earnings	$ 108,981		$ 78,992		$ 189,509	$ 154,338
Basic weighted-average common shares	527,781		394,574		524,428	387,563
Dilutive potential common shares	1,099		1,118		1,102	1,120
Dilutive weighted-average common shares	528,880		395,692		525,530	388,683