Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Non-cash investing and financing activities:
Fixed assets acquired with accounts payable or accrued liabilities	$ 14,331	$ 24,281
Conversion of convertible notes receivable into equity securities	0	4,862
Issuance of promissory note in exchange for sale of equity method investment	54,154	$ 0
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	21,186
Investing cash flows from finance leases	10,896
Financing cash flows from finance leases	45,773
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	26,395
Finance leases	$ 51,064