Acquisitions - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended			0 Months Ended		1 Months Ended	0 Months Ended	1 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	May 09, 2012	Nov. 30, 2014	Sep. 27, 2012	May 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Business Acquisition [Line Items]
Revenue	$ 200,731,000	$ 192,598,000	$ 188,722,000	$ 185,810,000	$ 182,522,000	$ 179,505,000	$ 177,457,000	$ 173,218,000	$ 767,861,000	$ 712,702,000	$ 551,842,000
The PORTIA Business [Member]
Business Acquisition [Line Items]
Consideration paid, net of cash plus the costs of transaction									169,161,000			170,000,000
Business acquisition, effective date of acquisition									May 09, 2012
The PORTIA Business [Member] | Doubtful [Member]
Business Acquisition [Line Items]
Fair value of acquired accounts receivable	1,200,000								1,200,000
The PORTIA Business [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Amortized period									10 years
The PORTIA Business [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Amortized period									9 years
The PORTIA Business [Member] | Completed Technology [Member]
Business Acquisition [Line Items]
Amortized period									7 years
The PORTIA Business [Member] | Non-Compete Agreements [Member]
Business Acquisition [Line Items]
Amortized period									3 years
DSTGS [Member]
Business Acquisition [Line Items]
Consideration paid, net of cash plus the costs of transaction									94,962,000				95,000,000
Business acquisition, effective date of acquisition									Nov. 30, 2014
Revenue									7,200,000
Estimated working capital adjustment to be paid in first quarter of 2015									8,000,000
DSTGS [Member] | Doubtful [Member]
Business Acquisition [Line Items]
Fair value of acquired accounts receivable	500,000								500,000
DSTGS [Member] | Customer Relationships [Member] | Minimum [Member]
Business Acquisition [Line Items]
Amortized period									10 years
DSTGS [Member] | Customer Relationships [Member] | Maximum [Member]
Business Acquisition [Line Items]
Amortized period									15 years
DSTGS [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Amortized period									10 years
DSTGS [Member] | Completed Technology [Member] | Minimum [Member]
Business Acquisition [Line Items]
Amortized period									7 years
DSTGS [Member] | Completed Technology [Member] | Maximum [Member]
Business Acquisition [Line Items]
Amortized period									8 years
Gravity [Member]
Business Acquisition [Line Items]
Consideration paid, net of cash plus the costs of transaction									5,734,000					5,700,000
Business acquisition, effective date of acquisition									Sep. 27, 2012
Gravity [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Amortized period									7 years
Gravity [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Amortized period									7 years
GlobeOp [Member]
Business Acquisition [Line Items]
Consideration paid, net of cash plus the costs of transaction									788,914,000						834,400,000
Business acquisition, effective date of acquisition									Jun. 01, 2012
GlobeOp [Member] | Doubtful [Member]
Business Acquisition [Line Items]
Fair value of acquired accounts receivable	300,000								300,000
GlobeOp [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Amortized period									9 years
GlobeOp [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Amortized period									17 years
GlobeOp [Member] | Completed Technology [Member]
Business Acquisition [Line Items]
Amortized period									8 years
Prime [Member]
Business Acquisition [Line Items]
Consideration paid, net of cash plus the costs of transaction																4,000,000
Hedgemetrix [Member]
Business Acquisition [Line Items]
Consideration paid, net of cash plus the costs of transaction																	$ 3,100,000