Allowance for Credit Losses and Credit Quality - Aged Analysis of Past Due Financing Receivables by Our Internally Developed Proprietary Scoring Model in Leases (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 147,865	$ 145,145
31 to 60 Days Past Due	4,948	6,144
61 to 90 Days Past Due	4,418	4,769
Over 90 Days Past Due	20,193	17,813
Financing receivables, Ending balance	177,424	173,871
Over 90 Days Accruing	20,193	17,813
Percent of total financing receivables, Current	83.30%	83.50%
Percent of total financing receivables, 31 to 60 Days Past Due	2.80%	3.50%
Percent of total financing receivables, 61 to 90 Days Past Due	2.50%	2.70%
Percent of total financing receivables, Over 90 Days Past Due	11.40%	10.30%
Percent of total financing receivables	100.00%	100.00%
Lease Comm [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	92	90
31 to 60 Days Past Due	4	5
61 to 90 Days Past Due	4	5
Over 90 Days Past Due	88	74
Financing receivables, Ending balance	188	174
Over 90 Days Accruing	88	74
Time Payment Corp [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	147,773	145,055
31 to 60 Days Past Due	4,944	6,139
61 to 90 Days Past Due	4,414	4,764
Over 90 Days Past Due	20,105	17,739
Financing receivables, Ending balance	177,236	173,697
Over 90 Days Accruing	20,105	17,739
Time Payment Corp [Member] | Gold [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	56,727	54,446
31 to 60 Days Past Due	1,782	2,763
61 to 90 Days Past Due	1,156	1,042
Over 90 Days Past Due	3,508	2,309
Financing receivables, Ending balance	63,173	60,560
Over 90 Days Accruing	3,508	2,309
Time Payment Corp [Member] | Silver [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	83,505	84,268
31 to 60 Days Past Due	2,671	2,883
61 to 90 Days Past Due	2,768	3,281
Over 90 Days Past Due	14,016	13,312
Financing receivables, Ending balance	102,960	103,744
Over 90 Days Accruing	14,016	13,312
Time Payment Corp [Member] | Bronze [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7,541	6,341
31 to 60 Days Past Due	491	493
61 to 90 Days Past Due	490	441
Over 90 Days Past Due	2,581	2,118
Financing receivables, Ending balance	11,103	9,393
Over 90 Days Accruing	$ 2,581	$ 2,118