Revenue by Geographic Region (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 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
Segment Reporting Information [Line Items]
Revenue	$ 186,203	$ 191,220	$ 194,441	$ 198,149	$ 198,718	$ 196,817	$ 200,058	$ 211,986	$ 770,013		$ 807,579		$ 890,392
United States
Segment Reporting Information [Line Items]
Revenue									484,252	[1]	500,746	[1]	517,268	[1]
International
Segment Reporting Information [Line Items]
Revenue									$ 285,761	[1]	$ 306,833	[1]	$ 373,124	[1]

[1] Revenue by geographic region is generally based on the location of the Company's subsidiary.