Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Total revenues	$ 153,018	$ 127,788	$ 431,886	$ 382,766
United States	269,480		269,480		221,922
Total long-lived assets	269,480		269,480		221,922
UNITED STATES
Total revenues	101,381	90,447	289,656	270,444
United States	176,216		176,216		170,247
Total long-lived assets	176,216		176,216		170,247
CANADA
Total revenues	17,698	17,992	52,642	55,137
IRELAND
Total revenues	10,846	10,417	32,118	30,822
All Other Countries [Member]
Total revenues	23,093	8,932	57,470	26,363
United States	93,264		93,264		51,675
Total long-lived assets	$ 93,264		$ 93,264		$ 51,675