Debt - Activity Related to Repurchase of Debt and Net Loss on Early Extinguishment of Debt (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Original principal amount	$ 1,089,100		$ 2,033,600
Cash purchase/repayment price	1,102,000		2,104,800
Losses on early extinguishment of debt	16,126	$ 2,586	68,379
Senior Notes [Member]
Debt Instrument [Line Items]
Original principal amount	656,300		1,495,300
Cash purchase/repayment price	669,100		1,566,500
Secured Mortgage debt [Member]
Debt Instrument [Line Items]
Original principal amount	432,800		538,300
Cash purchase/repayment price	$ 432,900		$ 538,300