Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Total Revenues	$ 59,150	$ 81,198
Agency & Digital Services
Disaggregation of Revenue [Line Items]
Total Revenues	6,232
Database Marketing Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	$ 6,892
Contract period	four and five years
Database Marketing Solutions | Short-term Contract
Disaggregation of Revenue [Line Items]
Contract period	less than two months
Direct Mail, Logistics, and Fulfillment
Disaggregation of Revenue [Line Items]
Total Revenues	$ 30,288
Contact Centers
Disaggregation of Revenue [Line Items]
Total Revenues	$ 15,738
Contract period	six months to one year
Revenue for performance obligations recognized over time
Disaggregation of Revenue [Line Items]
Total Revenues	$ 52,776
Revenue for performance obligations recognized over time | Agency & Digital Services
Disaggregation of Revenue [Line Items]
Total Revenues	6,193
Revenue for performance obligations recognized over time | Database Marketing Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	6,106
Revenue for performance obligations recognized over time | Direct Mail, Logistics, and Fulfillment
Disaggregation of Revenue [Line Items]
Total Revenues	24,739
Revenue for performance obligations recognized over time | Contact Centers
Disaggregation of Revenue [Line Items]
Total Revenues	15,738
Revenue for performance obligations recognized at a point in time
Disaggregation of Revenue [Line Items]
Total Revenues	6,374
Revenue for performance obligations recognized at a point in time | Agency & Digital Services
Disaggregation of Revenue [Line Items]
Total Revenues	39
Revenue for performance obligations recognized at a point in time | Database Marketing Solutions
Disaggregation of Revenue [Line Items]
Total Revenues	786
Revenue for performance obligations recognized at a point in time | Direct Mail, Logistics, and Fulfillment
Disaggregation of Revenue [Line Items]
Total Revenues	5,549
Revenue for performance obligations recognized at a point in time | Contact Centers
Disaggregation of Revenue [Line Items]
Total Revenues	0
B2B
Disaggregation of Revenue [Line Items]
Total Revenues	12,785	18,882
Consumer Brands
Disaggregation of Revenue [Line Items]
Total Revenues	12,163	19,556
Financial Services
Disaggregation of Revenue [Line Items]
Total Revenues	12,965	14,645
Healthcare
Disaggregation of Revenue [Line Items]
Total Revenues	4,627	4,426
Retail
Disaggregation of Revenue [Line Items]
Total Revenues	12,311	15,673
Transportation
Disaggregation of Revenue [Line Items]
Total Revenues	$ 4,299	$ 8,016