Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 1,409	$ 1,368	$ 657
Charged to Cost and Expenses	812	354	941
Credited to Other Accounts	77	134	(65)
Amount Written Off	(369)	(447)	(165)
Balance at End of Period	5,050	1,409	1,368
Valuation Allowances and Reserves, Reserves of Businesses Acquired	3,121	0	0
Accounts Receivable
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	1,240	1,206	490
Charged to Cost and Expenses	727	453	941
Credited to Other Accounts	77	28	(60)
Amount Written Off	(369)	(447)	(165)
Balance at End of Period	4,796	1,240	1,206
Valuation Allowances and Reserves, Reserves of Businesses Acquired	3,121	0	0
Investment in sales-type leases
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	169	162	167
Charged to Cost and Expenses	85	(99)	0
Credited to Other Accounts	0	106	(5)
Amount Written Off	0	0	0
Balance at End of Period	254	169	162
Valuation Allowances and Reserves, Reserves of Businesses Acquired	$ 0	$ 0	$ 0