Stock-Based Compensation - Equity-Classified Stock Compensation (Market Condition Grants of Restricted Shares) - Additional Information (Detail)				3 Months Ended				6 Months Ended	12 Months Ended
	Jun. 30, 2016 USD ($) Increment shares	Feb. 26, 2016 $ / shares shares	Jan. 31, 2015 shares	Mar. 31, 2016 USD ($)	Jun. 30, 2015 $ / shares shares	Mar. 31, 2015 shares	Dec. 31, 2014 shares	Jun. 30, 2016 USD ($) Increment $ / shares shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2012 shares	Dec. 31, 2011 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted shares vesting description								The restricted shares will vest in six increments based upon the price per share of the Company’s common stock during the term of their employment (or within sixty days after termination of employment by the Company without cause) meeting or exceeding the target trailing sixty-day average closing prices ranging from $36 per share for the first increment to $65 per share for the final increment.
Restricted share award closing prices range per share, Minimum | $ / shares		$ 75						$ 36
Restricted share award closing prices range per share, Maximum | $ / shares								$ 65
Restricted share award average closing prices, period								60 days
Number of increments had vested | Increment								6
Mr Albright [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted shares vesting description								The 26,000 shares of restricted Company common stock outstanding from these grants will vest in seven increments based upon the price per share of Company common stock during the term of his employment (or within sixty days after termination of employment by the Company without cause), meeting or exceeding the target trailing thirty-day average closing prices ranging from $60 per share for the first increment to $75 per share for the final increment.
Restricted share award closing prices range per share, Minimum | $ / shares					$ 60
Restricted share award closing prices range per share, Maximum | $ / shares					$ 75
Restricted share award average closing prices, period					30 days
Number of increments had vested | Increment	0							4
Mr Patten [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of increments had vested | Increment								4
Mr Smith [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted shares vesting description								The restricted stock will vest in two increments based upon the price per share of Company common stock during the term of their employment (or within sixty days after termination of employment by the Company without cause), meeting or exceeding the target trailing sixty-day average closing prices of $60 per share and $65 per share for the two increments.
Restricted share award closing prices range per share, Minimum | $ / shares								$ 60
Restricted share award closing prices range per share, Maximum | $ / shares								$ 65
Restricted share award average closing prices, period								60 days
Number of increments had vested | Increment								0
Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of increments had vested | Increment								0
Restricted Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation, shares, outstanding									2,400
Stock-based compensation expense | $				$ 1,600,000				$ 1,600,000	$ 676,000
Unrecognized compensation cost related to market condition non-vested restricted shares | $	$ 0							$ 0
Restricted Shares [Member] | 2010 Plan [Member] | Mr Albright [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation, Shares, Granted		4,000	8,000		94,000					96,000	96,000
Stock based compensation, shares, outstanding		26,000
Stock based compensation, shares, surrendered		72,000
Stock based compensation, shares, permanently surrendered		68,000
Restricted Shares [Member] | 2010 Plan [Member] | Mr Patten [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation, Shares, Granted										17,000	17,000
Restricted Shares [Member] | 2010 Plan [Member] | Mr Smith [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation, Shares, Granted							2,500
Restricted Shares [Member] | 2010 Plan [Member] | Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation, Shares, Granted						3,000
Inducement Grant of Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation, Shares, Granted								4,000
Stock based compensation, shares, outstanding	69,500							69,500	137,500
Unrecognized compensation cost related to market condition non-vested restricted shares | $	$ 160,000							$ 160,000
Weighted average period of compensation cost to be recognized								6 months