Summary of Capital Expenditures Including Accrued Amounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total capital expenditures	$ 114,747	$ 134,531	$ 415,441
Owned and managed
Segment Reporting Information [Line Items]
Total capital expenditures	83,757	108,241	382,781
Managed-only
Segment Reporting Information [Line Items]
Total capital expenditures	5,238	5,749	4,049
Corporate and Other
Segment Reporting Information [Line Items]
Total capital expenditures	$ 25,752	$ 20,541	$ 28,611