Balance Sheet Components - Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 812,000
Non-current operating lease liabilities	765,024
Total	887,522
Lease Cost:
Lease costs	104,000
Operating lease cost	43,000
Short-term lease cost	61,000
Cash paid for operating lease liabilities	37,653
Right-of-use assets obtained in exchange for new operating lease obligations	$ 842,395
Weighted-average remaining lease term	8 years 6 months
Weighted-average discount rate	5.70%
Operating leases commenced during period	$ 99,000
Maturities of Lease Liabilities
2020	167,238
2021	142,248
2022	133,824
2023	113,437
2024	109,572
Thereafter	477,116
Total lease liabilities	1,143,435
Less imputed interest	(255,913)
Current operating lease liabilities	122,498
Operating lease, liability, leases not commenced	$ 815,000
ASU 2016-02
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets		$ 743,000
Non-current operating lease liabilities		$ 813,000
Minimum
Lessee, Lease, Description [Line Items]
Lease term of contract	1 year
Lease renewal term	1 year
Maturities of Lease Liabilities
Lease not yet commenced, term of contract	5 years
Maximum
Lessee, Lease, Description [Line Items]
Lease term of contract	15 years
Lease renewal term	10 years
Maturities of Lease Liabilities
Lease not yet commenced, term of contract	15 years