Earnings Per Share - Calculation of Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 90,267	$ 79,920	$ 76,291	$ 736,476	$ 112,017	$ 91,043	$ 246,478	$ 939,536
Non-controlling interests’ share in net income	(481)			(442)			(1,432)	(1,334)
Participating securities’ share in earnings	(432)			(290)			(1,354)	(808)
Net income, less participating securities’ share in earnings	$ 89,354			$ 735,744			$ 243,692	$ 937,394
Basic weighted-average common shares	439,581			365,024			404,902	364,934
Dilutive potential common shares	1,352			1,443			1,198	850
Dilutive weighted-average common shares	440,933			366,467			406,100	365,784
MPT Operating Partnership, L.P. [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 90,267	$ 79,920	$ 76,291	$ 736,476	$ 112,017	$ 91,043	$ 246,478	$ 939,536
Non-controlling interests’ share in net income	(481)			(442)			(1,432)	(1,334)
Participating securities’ share in earnings	(432)			(290)			(1,354)	(808)
Net income, less participating securities’ share in earnings	$ 89,354			$ 735,744			$ 243,692	$ 937,394
Basic weighted-average common shares	439,581			365,024			404,902	364,934
Dilutive potential common shares	1,352			1,443			1,198	850
Dilutive weighted-average common shares	440,933			366,467			406,100	365,784