Segments - Schedule of Revenues and Long-Lived Assets by Geographical Area (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenues, net	$ 255,501	$ 225,150	$ 220,869	$ 193,651	$ 202,617	$ 186,932	$ 171,820	$ 146,165	$ 895,171	$ 707,534	$ 519,591
Long-lived assets (excluding goodwill)	1,025,998				599,907				1,025,998	599,907	464,165
UNITED STATES
Segment Reporting Information [Line Items]
Revenues, net									460,111	399,573	348,065
Long-lived assets (excluding goodwill)	173,354				152,175				173,354	152,175
UNITED KINGDOM
Segment Reporting Information [Line Items]
Revenues, net									198,762	153,305	80,778
Long-lived assets (excluding goodwill)	352,538				225,050				352,538	225,050
CZECHOSLOVAKIA
Segment Reporting Information [Line Items]
Revenues, net											54,542
Brazil [Member]
Segment Reporting Information [Line Items]
Long-lived assets (excluding goodwill)	$ 293,055				$ 81,934				$ 293,055	$ 81,934