Business Segment, Product, and Geographic Information 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
Revenues and Net Property and Equipment by Geographical Areas [Line Items]
Total revenues	$ 189,918	$ 169,156	$ 558,090	$ 494,358
Property, Plant and Equipment, Net	131,217		131,217		128,064
UNITED STATES
Revenues and Net Property and Equipment by Geographical Areas [Line Items]
Total revenues	164,805	152,377	490,274	450,024
Property, Plant and Equipment, Net	105,758		105,758		109,458
International [Member]
Revenues and Net Property and Equipment by Geographical Areas [Line Items]
Total revenues	25,113	16,779	67,816	44,334
Property, Plant and Equipment, Net	$ 25,459		$ 25,459		$ 18,606