Business and Basis of Presentation - Lease Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019
Operating Lease Payments
2019 (remaining nine months)	$ 92,379
2020	119,620
2021	115,734
2022	111,757
2023	107,466
Thereafter	681,210
Total future minimum operating lease payments and estimated sublease cash receipts	1,228,166
Imputed interest	(391,715)
Total per the Condensed Consolidated Balance Sheet	836,451	$ 851,300
Sublease Cash Receipts
2019 (remaining nine months)	26,754
2020	39,742
2021	41,475
2022	42,039
2023	42,953
Thereafter	171,154
Total future minimum operating lease payments and estimated sublease cash receipts (1)	$ 364,117