Quarterly Financial Data (Unaudited) - Unaudited Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information [Line Items]
Revenues	$ 180,578	$ 196,996	$ 201,902	$ 205,046	$ 204,961	$ 176,580	$ 166,807	$ 156,397	$ 784,522	$ 704,745	$ 541,137
Net income	78,941	736,476	112,017	91,043	72,376	76,881	73,796	68,185	1,018,477	291,238	225,937
Net income attributable to MPT common stockholders	$ 78,483	$ 736,034	$ 111,567	$ 90,601	$ 71,944	$ 76,464	$ 73,415	$ 67,970	$ 1,016,685	$ 289,793	$ 225,048
Net income attributable to MPT common stockholders (Operating Partnership partners)	$ 0.21	$ 2.01	$ 0.30	$ 0.25	$ 0.19	$ 0.21	$ 0.21	$ 0.21	$ 2.77	$ 0.82	$ 0.86
Weighted average shares outstanding — basic	366,655	365,024	364,897	364,882	364,382	364,315	349,856	321,057	365,364	349,902	260,414
Net income attributable to MPT common stockholders (Operating Partnership partners)	$ 0.21	$ 2.00	$ 0.30	$ 0.25	$ 0.19	$ 0.21	$ 0.21	$ 0.21	$ 2.76	$ 0.82	$ 0.86
Weighted average shares outstanding — diluted	367,732	366,467	365,541	365,343	364,977	365,046	350,319	321,423	366,271	350,441	261,072
MPT Operating Partnership, L.P. [Member]
Quarterly Financial Information [Line Items]
Revenues	$ 180,578	$ 196,996	$ 201,902	$ 205,046	$ 204,961	$ 176,580	$ 166,807	$ 156,397	$ 784,522	$ 704,745	$ 541,137
Net income	78,941	736,476	112,017	91,043	72,376	76,881	73,796	68,185	1,018,477	291,238	225,937
Net income attributable to MPT common stockholders	$ 78,483	$ 736,034	$ 111,567	$ 90,601	$ 71,944	$ 76,464	$ 73,415	$ 67,970	$ 1,016,685	$ 289,793	$ 225,048
Net income attributable to MPT common stockholders (Operating Partnership partners)	$ 0.21	$ 2.01	$ 0.30	$ 0.25	$ 0.19	$ 0.21	$ 0.21	$ 0.21	$ 2.77	$ 0.82	$ 0.86
Weighted average shares outstanding — basic	366,655	365,024	364,897	364,882	364,382	364,315	349,856	321,057	365,364	349,902	260,414
Net income attributable to MPT common stockholders (Operating Partnership partners)	$ 0.21	$ 2.00	$ 0.30	$ 0.25	$ 0.19	$ 0.21	$ 0.21	$ 0.21	$ 2.76	$ 0.82	$ 0.86
Weighted average shares outstanding — diluted	367,732	366,467	365,541	365,343	364,977	365,046	350,319	321,423	366,271	350,441	261,072