Long-Term Incentive Plans - Summary of Amount of Compensation Expense Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense (benefit)	$ 828	$ 1,068	$ 2,898	$ 1,561
TSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense (benefit)	650	490	1,852	601
PSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense (benefit)	120	495	825	747
Board RSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense (benefit)	58	44	221	98
Restricted Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense (benefit)	$ 0	$ 39	$ 0	$ 115