Fair Value Of Financial Instruments (Narrative) (Detail) (USD $)	12 Months Ended				3 Months Ended	24 Months Ended	12 Months Ended							12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Senior Notes [Member] Unsecured Debt [Member] Total Senior And Senior Convertible Notes [Member]	Mar. 31, 2013 Senior Notes [Member] Unsecured Debt [Member] 7.625% Senior Notes [Member]	Dec. 31, 2013 2013 and 2012 Acquisitions [Member]	Dec. 31, 2013 Earn-out Arrangements [Member]	Dec. 31, 2012 Earn-out Arrangements [Member]	Dec. 31, 2013 Earn-out Arrangements [Member] Accumulated Translation Adjustment [Member]	Dec. 31, 2012 Earn-out Arrangements [Member] Accumulated Translation Adjustment [Member]	Dec. 31, 2013 Auction Rate Securities [Member]	Dec. 31, 2012 Auction Rate Securities [Member]	Dec. 31, 2012 Auction Rate Securities [Member] Fair Value [Member]	Dec. 31, 2013 Auction Rate Securities [Member] Securities Redeemed or Sold [Member]	Dec. 31, 2013 Cash Surrender Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Non-Recurring Basis [Line Items]
Fair value measurements, valuation techniques				The estimated fair values of the Company’s 4.875% Senior Notes, 7.625% Senior Notes, 2009 Convertible Notes and 2011 Convertible Notes are based on quoted market prices, a Level 1 input.			The fair value of such acquisition-related contingent consideration is based on management’s estimates and entity-specific assumptions and is evaluated on an on-going basis.				their respective fair values were estimated by an independent valuation firm, Houlihan Capital Advisors, LLC, using a probability weighted discounted cash flow model.				Cash surrender values of life insurance policies are based on current cash surrender values as quoted by insurance carriers.
Proceeds from sale and redemption of available-for-sale securities	$ 14,956,000	$ 0	$ 4,600,000											$ 15,000,000
Net realized gain, available-for-sale securities														400,000
Fair value, available-for-sale securities													14,400,000
Unrealized losses, net, available-for-sale securities												200,000
Number of acquisitions						6
Additions from new business combinations, contingent consideration							30,000,000	66,700,000
Payments of contingent consideration							8,500,000	3,800,000
Foreign currency translation adjustments, contingent consideration									2,200,000	100,000
Loss on extinguishment of debt	$ 5,624,000	$ 0	$ 0		$ 5,600,000