Segment Reporting - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Revenue, Major Customer [Line Items]
Total consolidated revenue from customer	[1]	$ 253,636	$ 228,332	$ 714,032	$ 676,105
American Express Corp.
Revenue, Major Customer [Line Items]
Total consolidated revenue from customer		$ 53,700	$ 51,300	$ 147,700	$ 147,500
Percent of total consolidated revenues from customer		21.20%	22.50%	20.70%	21.80%
Accounts receivable from customer		$ 21,700		$ 21,700		$ 19,000
State Street Bank
Revenue, Major Customer [Line Items]
Total consolidated revenue from customer		$ 38,100	$ 31,200	$ 102,900	$ 94,900
Percent of total consolidated revenues from customer		15.00%	13.70%	14.40%	14.00%
Accounts receivable from customer		$ 17,100		$ 17,100		11,300
Federal Express Corp.
Revenue, Major Customer [Line Items]
Total consolidated revenue from customer		$ 30,400	$ 25,400	$ 89,200	$ 76,400
Percent of total consolidated revenues from customer		12.00%	11.10%	12.50%	11.30%
Accounts receivable from customer		$ 12,800		$ 12,800		$ 14,300
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 Corp.
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.