Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities - Significant Non-Cash Investing and Financing Activities (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013
Supplemental Cash Flow Elements [Abstract]
Interest	$ 19,940	$ 13,223
Income taxes	92,018	81,156
Other payable issued for purchased customer accounts	1,623	503
Estimated acquisition earn-out payables and related charges	12,937	2,064
Notes received on the sale of fixed assets and customer accounts	$ 296	$ 1,107

Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities - Significant Non-Cash Investing and Financing Activities (Detail) (USD $)
In Thousands, unless otherwise specified

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Supplemental Cash Flow Elements [Abstract]

Interest

$ 19,940

$ 13,223

Income taxes

92,018

81,156

Other payable issued for purchased customer accounts

1,623

503

Estimated acquisition earn-out payables and related charges

12,937

2,064

Notes received on the sale of fixed assets and customer accounts

$ 296

$ 1,107