Deferred Revenue (Tables)

12 Months Ended

Dec. 31, 2015

Deferred Revenue Disclosure [Abstract]

Components of Deferred Revenue

Deferred revenue consists of the following (in thousands):

	December 31,
	2015		2014
Future service	$	22,112	$	25,222
Estimated potential penalties and holdbacks		6,007		9,023
	$	28,119	$	34,245