XML 52 R40.htm IDEA: XBRL DOCUMENT v3.7.0.1
Summary of Performance-based Award Activity (Detail) - Performance Shares
3 Months Ended
Mar. 31, 2017
USD ($)
$ / shares
shares
Number of shares  
Beginning balance | shares 145,962 [1]
Cancellations | shares (250) [1]
Ending balance | shares 145,712 [1]
Total unrecognized compensation expense remaining | $ $ 1,143,000 [1]
Weighted-average years expected to be recognized over 1 year 6 months [1]
Weighted-average grant date fair value  
Beginning balance | $ / shares $ 15.32
Cancellations | $ / shares 14.84
Ending balance | $ / shares $ 15.32
[1] Represents the target number of shares to be issued for each performance-based award.