Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities - Significant Non-Cash Investing and Financing Activities (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash paid during the period for:
Interest	$ 33,091	$ 19,940
Income taxes	96,579	92,018
Significant non-cash investing and financing activities
Other payable issued for purchased customer accounts	995	1,623
Estimated acquisition earn-out payables and related charges	29,497	12,937
Notes received on the sale of fixed assets and customer accounts	$ 544	$ 296