Stock-Based Compensation - Summary of Stock Option Activity (Detail) - $ / shares shares in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Shares
Exercised (in shares)	(10)
Stock options
Shares
Beginning balance (in shares)	3,075	3,111
Granted (in shares)	30	0
Exercised (in shares)	(10)	0
Canceled, expired or forfeited (in shares)	0	(1)
Ending balance (in shares)	3,095	3,110
Weighted Average Exercise Price Per Share
Beginning balance (in dollars per share)	$ 20.12	$ 20.26
Granted (in dollars per share)	30.54	0.00
Exercised (in dollars per share)	18.00	0.00
Canceled, expired or forfeited (in dollars per share)	0.00	589.41
Ending balance (in dollars per share)	$ 20.23	$ 20.19