Equity Compensation Plans - 2001 Plan and 2005 Plan - Additional Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended							3 Months Ended						1 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Minimum [Member]	Mar. 31, 2014 Maximum [Member]	Mar. 31, 2014 2001 Plan [Member]	Mar. 31, 2014 2005 Plan [Member]	Dec. 31, 2013 2005 Plan [Member]	Mar. 31, 2014 Employee Stock Option [Member]	Mar. 31, 2014 Employee Stock Option [Member] 2001 Plan [Member]	Mar. 31, 2014 Employee Stock Option [Member] 2005 Plan [Member]	Mar. 31, 2014 Restricted Stock [Member]	Mar. 31, 2013 Restricted Stock [Member]	Mar. 31, 2014 Restricted Stock [Member] 2005 Plan [Member]	Nov. 30, 2012 Performance Shares [Member]	Mar. 31, 2014 Performance Shares [Member]	Mar. 31, 2013 Performance Shares [Member]	Mar. 31, 2014 Time Based Stock Options and Restricted Stock [Member]	Mar. 31, 2013 Time Based Stock Options and Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry of options from the date of grant					10 years	10 years									10 years
Exercisable period beginning									1 year
Options granted exercisable cumulative									25.00%	25.00%
Restricted stock awards granted annual vest rate						25.00%
Options granted from the 2005 Plan generally vest													4 years
Common stock reserved for issuance						7,649	756
Percentage of outstanding shares of common stock on the first day						3.25%
Outstanding shares of common stock on the first day						825
Outstanding shares authorized on that date							3.25%
Shares available for future grants						1,067
Total intrinsic value of options exercised	$ 1,851	$ 464
Cash proceeds	1,395	1,002
Total fair value of performance shares vested															0	0
Total fair value of restricted stock vested											261	607
Tax benefit recognized	0	0
Recognized expense related to stock options and restricted stock	2,142	518															732	383
Unrecognized compensation costs related to non-vested share-based compensation arrangements with performance shares	18,471
Stock options compensation costs								10,303
Unrecognized compensation costs related to non-vested performance options											8,168				1,324
Weighted average period of recognizing cost			1 year 4 months 24 days	3 years 9 months 18 days				3 years			3 years 3 months 18 days
Performance options awarded to President and CEO	488													225
Number of shares options vest in															25
Period of considering closing price of common stock															30 days
Price by which volume adjusted weighted average closing price exceeds under vesting condition 1															$ 10.00
Price by which volume adjusted weighted average closing price exceeds under vesting condition 2															$ 12.50
Price by which volume adjusted weighted average closing price exceeds under vesting condition 3															$ 15.00
Price by which volume adjusted weighted average closing price exceeds under vesting condition 4															$ 17.50
Price by which volume adjusted weighted average closing price exceeds under vesting condition 5															$ 20.00
Price by which volume adjusted weighted average closing price exceeds under vesting condition 6															$ 25.00
Price by which volume adjusted weighted average closing price exceeds under vesting condition 7															$ 30.00
Price by which volume adjusted weighted average closing price exceeds under vesting condition 8															$ 35.00
Price by which volume adjusted weighted average closing price exceeds under vesting condition 9															$ 40.00
Recognized expense related to performance options	$ 2,142	$ 518													$ 1,302	$ 38
Performance option exercisable	1,274														250