Fair Value Measurements - Change in Estimated Fair Value Calculated for Liabilities Valued on Recurring Basis Utilizing Level 3 Inputs (Detail) - Significant Unobservable Inputs (Level 3) [Member] - Contingent Consideration Obligations [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at the beginning of the period	$ 144
Obligation incurred upon acquisition of noncontrolling interest	208
Payments	(99)
Balance at the end of the period	$ 253