Equity Compensation Plans - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended	12 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 07, 2013 Amended and Restated 2006 Equity Compensation Plan [Member]	Dec. 31, 2013 2006 Equity Compensation Plan [Member]	May 07, 2013 2006 Equity Compensation Plan [Member]	Dec. 31, 2013 2006 Equity Compensation Plan [Member] Awards Prior To November 24, 2010 [Member] Y	Dec. 31, 2013 2006 Equity Compensation Plan [Member] Awards After November 24, 2010 [Member] Y	Dec. 31, 2013 1999 Directors Stock Plan [Member]	Dec. 31, 2013 1999 Directors Stock Plan [Member] Maximum [Member] Stock Options Granted Prior To January 25, 2005 [Member]	Dec. 31, 2013 1999 Directors Stock Plan [Member] Maximum [Member] Stock Options Granted On Or After January 25, 2005 [Member]	Dec. 31, 2013 1997 Stock Plan [Member]	Dec. 31, 2013 1997 Stock Plan [Member] Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares of common stock authorized for grant				7,350,000		4,000,000			500,000			8,100,000
Increase in number of shares of common stock authorized for grant				3,350,000
Maximum percentage of shares on cumulative basis used for restricted stock awards												20.00%
Maximum percentage available for issuance of incentive stock option plan												1.50%
Capitalization of stock-based compensation cost	$ 0	$ 0	$ 0
Pre-tax compensation expense for unvested stock-based compensation grants	13,900,000
Service period applicable to the grantees on a weighted-average basis, years	2 years
Maximum term of Stock Options granted under stock option plan					7 years					10 years	7 years		10 years 2 days
Award vesting period									Under the 1999 Directors Stock Plan, the stock options granted typically vested and became exercisable on the first anniversary of the grant.			Vested and became exercisable in three equal annual installments commencing with the first anniversary of the date of grant.
Share based compensation by share based payment, restriction period							3	1
Number of RSUs vested in the period that were settled in cash		48,935
RSUs vested and settled in shares of common stock, amount	1,241,000	4,568,000	2,454,000
RSUs vested and settled in cash, amount		$ 3,073,000