Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets:
Total assets measured at fair value	$ 3,055	$ 3,056
Liabilities:
Total liabilities measured at fair value	7,735	8,808
Senior Credit Facility [Member]
Liabilities:
Total liabilities measured at fair value	0	0
Money Market Funds [Member]
Assets:
Total assets measured at fair value	3,055	3,056
Contingent consideration [Member]
Liabilities:
Total liabilities measured at fair value	7,735	8,808
Level 1 [Member]
Assets:
Total assets measured at fair value	3,055	3,056
Liabilities:
Total liabilities measured at fair value	0	0
Level 1 [Member] | Senior Credit Facility [Member]
Liabilities:
Total liabilities measured at fair value	0	0
Level 1 [Member] | Money Market Funds [Member]
Assets:
Total assets measured at fair value	3,055	3,056
Level 1 [Member] | Contingent consideration [Member]
Liabilities:
Total liabilities measured at fair value	0	0
Level 2 [Member]
Assets:
Total assets measured at fair value	0	0
Liabilities:
Total liabilities measured at fair value	0	0
Level 2 [Member] | Senior Credit Facility [Member]
Liabilities:
Total liabilities measured at fair value	0	0
Level 2 [Member] | Money Market Funds [Member]
Assets:
Total assets measured at fair value	0	0
Level 2 [Member] | Contingent consideration [Member]
Liabilities:
Total liabilities measured at fair value	0	0
Level 3 [Member]
Assets:
Total assets measured at fair value	0	0
Liabilities:
Total liabilities measured at fair value	7,735	8,808
Level 3 [Member] | Senior Credit Facility [Member]
Liabilities:
Total liabilities measured at fair value	0	0
Level 3 [Member] | Money Market Funds [Member]
Assets:
Total assets measured at fair value	0	0
Level 3 [Member] | Contingent consideration [Member]
Liabilities:
Total liabilities measured at fair value	$ 7,735	$ 8,808