Acquisitions and Dispositions - Fair Value, Valuation Techniques and Related Unobservable Inputs (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Customer Relationships
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 11.0	$ 4.9
Customer Relationships | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair Value	$ 4.6
Discount rate	13.00%
Attrition rate	5.00%	2.70%
Customer Relationships | Fair Value, Inputs, Level 3 | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Discount rate			12.00%
Attrition rate			6.60%
Customer Relationships | Fair Value, Inputs, Level 3 | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Discount rate			18.00%
Attrition rate			12.00%
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	$ 0.3
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	$ 11.0
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 or without method
Discount rate	16.00%
Four Insignificant Acquisitions | 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		$ 4.9
Valuation Technique	Excess earnings
Four Insignificant Acquisitions | 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		15.00%
Attrition rate		5.00%
Four Insignificant Acquisitions | 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		10.00%
Four Insignificant Acquisitions | 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%
Consolidated Graphics, Inc | 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			$ 161.6
Valuation Technique	Excess earnings
Consolidated Graphics, Inc | 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			17.00%
Attrition rate			5.00%
Consolidated Graphics, Inc | 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			19.00%
Attrition rate			15.00%
Consolidated Graphics, Inc | 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			$ 17.7
Valuation Technique	Relief-from-royalty method
Discount rate			19.00%
Royalty rate (pre-tax)			0.50%