Quarterly report pursuant to Section 13 or 15(d)

STOCKHOLDERS' EQUITY - Summary of Changes in Shareholders' Equity (Details)

v3.7.0.1
STOCKHOLDERS' EQUITY - Summary of Changes in Shareholders' Equity (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Beginning balance (in shares)     40,030,518  
Beginning balance     $ 1,421,495 $ 1,258,937
Net earnings $ 41,580 $ 39,878 65,152 60,847
Exercise/vesting of stock-based awards     0 232
Excess income tax provision from stock-based awards       (526)
Stock-based compensation expense     $ 5,792 7,313
Ending balance (in shares) 40,320,282   40,320,282  
Ending balance $ 1,492,439 $ 1,326,803 $ 1,492,439 $ 1,326,803
Common Stock [Member]        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Beginning balance (in shares)     40,031,000 39,669,000
Beginning balance     $ 400 $ 397
Exercise/vesting of stock-based awards (in shares)     289,000 349,000
Exercise/vesting of stock-based awards     $ 3 $ 3
Ending balance (in shares) 40,320,000 40,018,000 40,320,000 40,018,000
Ending balance $ 403 $ 400 $ 403 $ 400
Additional Paid-in Capital [Member]        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Beginning balance     572,506 559,492
Exercise/vesting of stock-based awards     (3) 229
Excess income tax provision from stock-based awards       (526)
Stock-based compensation expense     5,792 7,313
Ending balance 578,295 566,508 578,295 566,508
Retained Earnings [Member]        
Increase (Decrease) in Stockholders' Equity [Roll Forward]        
Beginning balance     848,589 699,048
Net earnings     65,152 60,847
Ending balance $ 913,741 $ 759,895 $ 913,741 $ 759,895