Segment Reporting - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Revenue, Major Customer [Line Items]
Total consolidated revenue from customer	[1]	$ 231,340	$ 241,255	$ 684,020	$ 728,663
American Express Corp.
Revenue, Major Customer [Line Items]
Total consolidated revenue from customer		$ 33,500	$ 50,900	$ 113,300	$ 159,900
Percent of total consolidated revenues from customer		14.50%	21.10%	16.60%	21.90%
Accounts receivable from customer		$ 11,400		$ 11,400		$ 24,300
State Street Bank
Revenue, Major Customer [Line Items]
Total consolidated revenue from customer		$ 35,100	$ 32,800	$ 103,000	$ 100,200
Percent of total consolidated revenues from customer		15.20%	13.60%	15.10%	13.70%
Accounts receivable from customer		$ 16,300		$ 16,300		10,900
Federal Express Corporation
Revenue, Major Customer [Line Items]
Total consolidated revenue from customer		$ 33,100	$ 30,200	$ 94,900	$ 89,500
Percent of total consolidated revenues from customer		14.30%	12.50%	13.90%	12.30%
Accounts receivable from customer		$ 16,900		$ 16,900		$ 17,800
Sales Revenue, Net | Customer Concentration Risk | American Express Corp.
Revenue, Major Customer [Line Items]
Concentration of sales by customer		10.00%		10.00%
Sales Revenue, Net | Customer Concentration Risk | State Street Bank
Revenue, Major Customer [Line Items]
Concentration of sales by customer		10.00%		10.00%
Sales Revenue, Net | Customer Concentration Risk | Federal Express Corporation
Revenue, Major Customer [Line Items]
Concentration of sales by customer		10.00%		10.00%

[1] Net revenues are attributed to regions based upon customer location.