Acquisitions and Dispositions - Fair Value, Valuation Techniques and Related Unobservable Inputs (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 14.7
Customer Relationships
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	11.6
Trade Names
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	1.4
Non-Compete Agreements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	1.7
Precision Dialogue Holdings, LLC | Customer Relationships | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 11.6
Valuation Technique	Excess earnings
Discount rate	16.00%
Precision Dialogue Holdings, LLC | Customer Relationships | Fair Value, Inputs, Level 3 | Minimum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Attrition rate	7.00%
Precision Dialogue Holdings, LLC | Customer Relationships | Fair Value, Inputs, Level 3 | Maximum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Attrition rate	8.00%
Precision Dialogue Holdings, LLC | Trade Names | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 1.4
Valuation Technique	Relief-from-royalty method
Discount rate	16.00%
Precision Dialogue Holdings, LLC | Trade Names | Fair Value, Inputs, Level 3 | Minimum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Royalty rate (pre-tax)	0.75%
Precision Dialogue Holdings, LLC | Trade Names | Fair Value, Inputs, Level 3 | Maximum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Royalty rate (pre-tax)	1.25%
Precision Dialogue Holdings, LLC | Technology | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 0.6
Valuation Technique	Relief-from-royalty method
Discount rate	16.00%
Royalty rate (pre-tax)	15.00%
Precision Dialogue Holdings, LLC | Technology | Fair Value, Inputs, Level 3 | Minimum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Obsolescence factor	0.00%
Precision Dialogue Holdings, LLC | Technology | Fair Value, Inputs, Level 3 | Maximum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Obsolescence factor	40.00%
Precision Dialogue Holdings, LLC | Non-Compete Agreements | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 1.7
Valuation Technique	With and without method
Discount rate	16.00%
Courier Corporation | Customer Relationships | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 98.4
Valuation Technique	Excess earnings
Courier Corporation | Customer Relationships | Fair Value, Inputs, Level 3 | Minimum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Discount rate	14.00%
Attrition rate	0.00%
Courier Corporation | Customer Relationships | Fair Value, Inputs, Level 3 | Maximum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Discount rate	17.00%
Attrition rate	7.50%
Courier Corporation | Trade Names | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 10.1
Valuation Technique	Relief-from-royalty method
Discount rate	12.00%
Courier Corporation | Trade Names | Fair Value, Inputs, Level 3 | Minimum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Royalty rate (pre-tax)	0.30%
Courier Corporation | Trade Names | Fair Value, Inputs, Level 3 | Maximum | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Royalty rate (pre-tax)	1.00%
Courier Corporation | Technology | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 1.6
Valuation Technique	Relief-from-royalty method
Discount rate	11.00%
Royalty rate (pre-tax)	15.00%
Courier Corporation | Non-Compete Agreements | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 0.3
Valuation Technique	Excess earnings
Discount rate	17.00%