Leases - (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) ft²	Mar. 31, 2019 USD ($)	Dec. 31, 2019
Lease terms
Option to extend	20 years
Weighted-average remaining lease term	9 years		9 years
Weighted average discount rate - Operating leases	4.90%		4.90%
Increase in Right-of-Use Asset	$ 7,646
Increase in operating lease liability	1,000
Lease expense
Operating lease expense	6,862	$ 6,396
Variable lease expense	1,537	1,292
Rent expense	$ 8,399	$ 7,688
Minimum
Lease terms
Remaining lease terms	1 year
Maximum
Lease terms
Remaining lease terms	15 years
DC2 Washington DC
Lease terms
Net Leased Space | ft²	25,000
Increase in Right-of-Use Asset	$ 7,000