Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Leases, Operating [Abstract]
Carrying value of operating lease equipment after depreciation	$ 110,371	$ 74,143
Accumulated depreciation	33,630	29,620
Minimum future lease rental payments due from clients
Total	81,650
2016	22,080
2017	19,350
2018	16,020
2019	11,520
2020	11,010
Thereafter	1,670
Depreciation expense related to operating lease equipment	$ 18,280	$ 13,893	$ 13,055