Earnings Per Common Share - Schedule of Antidilutive Shares Excluded from Computation of Earnings Per Share (Detail) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Equivalent Shares (if converted)	1,649,282	1,945,123
Series B Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Equivalent Shares (if converted)	436,254	498,183
Series C Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Equivalent Shares (if converted)	129,763	352,385
Series D Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Equivalent Shares (if converted)	1,083,265	1,094,555