Finance Assets (Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Credit Losses
Balance at	$ 20,500	$ 21,690	$ 28,004
Amounts charged to expense	15,607	13,371	11,388
Accounts written off	(17,474)	(14,561)	(17,702)
Balance at	18,633	20,500	21,690
Sales-type lease receivables | North America
Allowance for Credit Losses
Balance at	8,247	6,606	10,125
Amounts charged to expense	7,544	5,136	1,189
Accounts written off	(8,070)	(3,495)	(4,708)
Balance at	7,721	8,247	6,606
Sales-type lease receivables | International
Allowance for Credit Losses
Balance at	2,647	3,542	5,023
Amounts charged to expense	1,280	1,161	890
Accounts written off	(1,133)	(2,056)	(2,371)
Balance at	2,794	2,647	3,542
Loan receivables | North America
Allowance for Credit Losses
Balance at	8,517	10,024	11,068
Amounts charged to expense	6,273	6,238	8,286
Accounts written off	(7,692)	(7,745)	(9,330)
Balance at	7,098	8,517	10,024
Loan receivables | International
Allowance for Credit Losses
Balance at	1,089	1,518	1,788
Amounts charged to expense	510	836	1,023
Accounts written off	(579)	(1,265)	(1,293)
Balance at	$ 1,020	$ 1,089	$ 1,518