Stockholder's Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Document Fiscal Year Focus	2016
Stockholders' Equity Note [Abstract]
Common stock reserved and available for issuance	1,500,000
Common stock shares available for grant	309,937
Percentage of directors' stock grant vested on one year anniversary date	100.00%
Period of Vested Shares	5 years
Granted, Weighted average grant date fair value | $ / shares	$ 37.43
Share based award, settled in cash	1,700
Total unrecognized compensation cost related to nonvested shares of common stock granted | $	$ 13,700
Weighted average period of cost recognized	3 years 5 months 19 days
Total fair value of shares of common stock vested | $	$ 3,600
Compensation expense related to nonvested stock grants | $	$ 1,000
Price of shares issued under Employee Stock Purchase Plan as a percentage of FMV	95.00%
Number of shares reserved for the Employee Stock Purchase Plan	250,000
Additional shares authorized for issuance	250,000
Stock options issued and exercisable	5,500
Options exercised	0
Options granted	0
Shares redeemed to satisfy personal tax obligations	37,962
Treasury shares redeemed to pay income tax | $	$ 1,421
Director
Stockholders' Equity Note [Abstract]
Non vested stock grants to Independent director	15,300
Director Period of Vested Shares	1 year
Employee
Stockholders' Equity Note [Abstract]
Nonvested stock grants to employees	165,800