Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities - Significant Non-Cash Investing and Financing Activities (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash paid during the period for:
Interest	$ 18,766	$ 11,070
Income taxes	67,457	58,079
Significant non-cash investing and financing activities
Other payable issued for purchased customer accounts	905	125
Estimated acquisition earn-out payables and related charges	27,134	13,158
Notes received on the sale of fixed assets and customer accounts	$ 544	$ 131