Net Income Per Operating Partnership Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net income	$ 58,169	$ 46,692
Numerator:
Net income	58,169	46,692
MGP Operating Partnership
Numerator:
Net income	$ 58,169	$ 46,692
Denominator:
Basic weighted average Operating Partnership units outstanding (in shares)	266,104,264	242,868,331
Basic net income per Operating Partnership Unit (in dollars per share)	$ 0.22	$ 0.19
Numerator:
Net income	$ 58,169	$ 46,692
Denominator:
Basic weighted average Operating Partnership units outstanding (in shares)	266,104,264	242,868,331
Effect of dilutive shares for diluted net income per Operating Partnership unit (in shares)	160,779	278,045
Weighted average shares for diluted net income per Operating Partnership unit (in shares)	266,265,043	243,146,376
Diluted net income per Operating Partnership unit (in dollars per share)	$ 0.22	$ 0.19