Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Total revenues	$ 127,788	$ 93,246	$ 382,766	$ 269,363
United States	194,143		194,143		152,103
Total long-lived assets	194,143		194,143		152,103
UNITED STATES
Total revenues	90,447	58,194	270,444	167,211
United States	146,039		146,039		105,549
Total long-lived assets	146,039		146,039		105,549
CANADA
Total revenues	17,992	20,028	55,137	60,616
IRELAND
Total revenues	10,417	10,124	30,822	30,908
All Other Countries [Member]
Total revenues	8,932	4,900	26,363	10,628
United States	48,104		48,104		46,554
Total long-lived assets	$ 48,104		$ 48,104		$ 46,554