Finance Assets (Aging of Receivables) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	$ 1,623,349	$ 1,689,473
1 - 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	1,565,324	1,621,914
Contract value	1,565,324	1,621,914
Greater than 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	58,025	67,559
Still accruing interest	7,969	12,545
Not accruing interest	50,056	55,014
Contract value	58,025	67,559
Sales-type lease receivables | North America
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,004,241	1,023,549
Sales-type lease receivables | North America | 1 - 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	961,356	971,002
Contract value	961,356	971,002
Sales-type lease receivables | North America | Greater than 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	42,885	52,547
Still accruing interest	6,297	10,807
Not accruing interest	36,588	41,740
Contract value	42,885	52,547
Sales-type lease receivables | International
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	273,118	292,059
Sales-type lease receivables | International | 1 - 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	266,146	286,170
Contract value	266,146	286,170
Sales-type lease receivables | International | Greater than 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	6,972	5,889
Still accruing interest	1,672	1,738
Not accruing interest	5,300	4,151
Contract value	6,972	5,889
Loan receivables | North America
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	313,049	339,373
Loan receivables | North America | 1 - 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	305,116	330,503
Contract value	305,116	330,503
Loan receivables | North America | Greater than 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	7,933	8,870
Still accruing interest	0	0
Not accruing interest	7,933	8,870
Contract value	7,933	8,870
Loan receivables | International
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	32,941	34,492
Loan receivables | International | 1 - 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	32,706	34,239
Contract value	32,706	34,239
Loan receivables | International | Greater than 90 days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing receivables	235	253
Still accruing interest	0	0
Not accruing interest	235	253
Contract value	$ 235	$ 253