Stockholders' Equity - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended						1 Months Ended			12 Months Ended	1 Months Ended	9 Months Ended
	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Net Share Settlements	Dec. 31, 2011 Net Share Settlements	Dec. 31, 2012 Share Repurchase Program	Jan. 31, 2012 Restricted Stock	Feb. 28, 2011 Restricted Stock	Mar. 31, 2010 Restricted Stock	Dec. 31, 2012 Restricted Stock	Mar. 31, 2011 Three-Year Period Restricted Stock	Mar. 31, 2012 Three-Year Period Restricted Stock	Mar. 31, 2012 Four-Year Period Restricted Stock
Class of Stock [Line Items]
Common stock, shares authorized		80,000,000	80,000,000
Common stock, par value		$ 0.01	$ 0.01
Restricted stock granted		895,457						161,785	285,281	79,500	42,513
Percentage of target number of shares								111.00%	150.00%	30.00%	25.00%
Restricted shares of common stock vesting period, (in years)	5 years							3 years	3 years	3 years	3 years	3 years	3 years	4 years
Restricted shares of common stock granted	588,600											510,399	646,438	179,000
Common stock issued from treasury stock		133,200
Issued common stock for the exercise of stock options		0
Repurchase of basic share of common stock							$ 50,000,000
Treasury shares acquired, total price		18,497,000	1,872,000	359,000			14,900,000
Treasury shares acquired, shares					357,714	79,730	1,558,394
Common stock repurchase, average cost per share							$ 9.54
Additional repurchase of Basic's shares of common stock							$ 20,300,000
Preferred stock, shares authorized		5,000,000	5,000,000
Preferred stock, par value		$ 0.01	$ 0.01
Preferred stock, shares issued
Preferred stock, shares outstanding		0	0