Earnings Per Share/Unit - Calculation of Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 163,880	$ 81,157
Non-controlling interests’ share in net income	(97)	(165)
Participating securities’ share in earnings	(370)	(464)
Net income, less participating securities’ share in earnings	$ 163,413	$ 80,528
Basic weighted-average common shares	576,240	521,076
Dilutive potential common shares	1,301	1,103
Diluted weighted-average common shares	577,541	522,179
MPT Operating Partnership, L.P. [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 163,880	$ 81,157
Non-controlling interests’ share in net income	(97)	(165)
Participating securities’ share in earnings	(370)	(464)
Net income, less participating securities’ share in earnings	$ 163,413	$ 80,528
Basic weighted-average common shares	576,240	521,076
Dilutive potential common shares	1,301	1,103
Diluted weighted-average common shares	577,541	522,179