Recent Accounting Standards - Additional Information (Detail) - USD ($)	Jan. 01, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Recognition of additional ROU assets		$ 87,743,000	$ 0
Recognition of additional lease liabilities		$ 115,763,000
ASU 2016-02
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Recognition of additional ROU assets	$ 88,800,000
Recognition of additional lease liabilities	116,900,000
Reductions in deferred rent	28,500,000
Reductions in prepaid expenses	400,000
Cumulative-effect adjustment to retained earnings	$ 0