Debt - Long-Term Debt Maturities (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
2017	$ 802,810
2018	746,068
2019	1,065,738
2020	1,282,003
2021	1,390,955
2022	1,359,481
2023	1,929,933
2024	882,614
2025	886,871
2026	536,469
Thereafter	113,840
Subtotal	10,996,782
Premiums (discounts), net	17,095
Debt issuance costs, net	(46,945)
Totals	10,966,932	$ 10,608,294
Senior Notes [Member]
Debt Instrument [Line Items]
2017	0
2018	175,000
2019	618,294
2020	844,077
2021	1,248,370
2022	748,370
2023	850,000
2024	748,370
2025	750,000
2026	534,550
Thereafter	0
Subtotal	6,517,031
Premiums (discounts), net	(19,003)
Debt issuance costs, net	(26,916)
Totals	6,471,112	6,417,492
Term Loans And Other Debt [Member]
Debt Instrument [Line Items]
2017	378,334
2018	961
2019	1,084
2020	1,190
2021	1,012
2022	447,914
2023	905,517
2024	911
2025	976
2026	696
Thereafter	112,679
Subtotal	1,851,274
Premiums (discounts), net	0
Debt issuance costs, net	(10,874)
Totals	1,840,400	$ 1,499,001
Secured Mortgage Debt [Member]
Debt Instrument [Line Items]
2017	424,476
2018	570,107
2019	446,360
2020	436,736
2021	141,573
2022	163,197
2023	174,416
2024	133,333
2025	135,895
2026	1,223
Thereafter	1,161
Subtotal	2,628,477
Premiums (discounts), net	36,098
Debt issuance costs, net	(9,155)
Totals	$ 2,655,420