Stock Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended					6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014 Stock Options [Member]	Jun. 30, 2013 Stock Options [Member]	Jun. 30, 2014 Stock Options [Member]	Jun. 30, 2013 Stock Options [Member]	Jun. 30, 2014 Stock Options [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2013 Stock Options [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Stock Options [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2013 Stock Options [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Stock Options [Member] Unvested [Member]	Jun. 30, 2014 Nonvested Restricted Stock [Member]	Mar. 31, 2014 Nonvested Restricted Stock [Member]	Jun. 30, 2014 Nonvested Restricted Stock [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2013 Nonvested Restricted Stock [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Nonvested Restricted Stock [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2013 Nonvested Restricted Stock [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Nonvested Restricted Stock [Member] Unvested [Member]	Jun. 30, 2014 Performance Shares [Member]	Jun. 30, 2014 Performance Shares [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2013 Performance Shares [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Performance Shares [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2013 Performance Shares [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Cash Settled Performance Share Units [Member]	Jun. 30, 2014 Cash Settled Performance Share Units [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2013 Cash Settled Performance Share Units [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Cash Settled Performance Share Units [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2013 Cash Settled Performance Share Units [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Nonvested Stock Option [Member]	Mar. 31, 2014 Nonvested Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value per share (in dollars per share)			$ 6.11	$ 5.43	$ 6.49	$ 5.53
Stock option expense							$ 595	$ 517	$ 1,149	$ 925
Restricted stock expense														124	139	124	161
Performance share expense																				315	93	675	156
Performance period																			3 years					3 years
Performance share unit expense																									418	320	611	861
Number of Shares [Roll Forward]
Outstanding, beginning balance (in shares)	2,092,419	2,229,969
Granted (in shares)	38,788	20,000
Exercised (in shares)	(57,650)	(139,000)
Forfeited or expired (in shares)	(18,900)	(18,550)
Outstanding, ending balance (in shares)	2,054,657	2,092,419
Options exercisable (in shares)	1,028,619
Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning balance (in dollars per share)	$ 9.49	$ 9.39
Granted (in dollars per share)	$ 21.69	$ 17.66
Exercised (in dollars per share)	$ 6.98	$ 9.47
Forfeited or expired (in dollars per share)	$ 13.41	$ 6.99
Outstanding, ending balance (in dollars per share)	$ 9.76	$ 9.49
Exercisable, ending balance (in dollars per share)	$ 6.44
Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value exercised			766	1,123	2,407	1,889
Aggregate intrinsic value outstanding			22,526		22,526
Aggregate intrinsic value exercisable			14,665		14,665
Compensation cost and weighted average vesting period information [Line Items]
Total compensation cost related to unvested share-based awards not yet recognized											$ 5,502							$ 271
Weighted average vesting period											2 years 4 months 24 days							0 years 3 months 18 days
Nonvested Stock Options, Number of Shares [Roll Forward]
Nonvested, beginning balance (in shares)																													1,072,400	1,080,900
Granted (in shares)																													38,788	20,000
Vested during period (in shares)																													(66,250)	(22,500)
Forfeited (in shares)																													(18,900)	(6,000)
Nonvested, ending balance (in shares)																													1,026,038	1,072,400
Nonvested Stock Options, Weighted-Average Grant-Date Fair Value [Roll Forward]
Nonvested, beginning balance (in dollars per share)																													$ 6.59	$ 6.50
Granted (in dollars per share)																													$ 6.11	$ 7.21
Vested during period (in dollars per share)																													$ 3.28	$ 3.32
Forfeited (in dollars per share)																													$ 7.13	$ 5.21
Nonvested, ending balance (in dollars per share)																													$ 6.77	$ 6.59
Nonvested Restricted Stock, Number of Shares [Roll Forward]
Nonvested, beginning balance (in shares)												0	0
Granted (in shares)												18,906	0
Vested during period (in shares)												0	0
Forfeited (in shares)												0	0
Nonvested, ending balance (in shares)												18,906	0
Nonvested Restricted Stock, Weighted-Average Grant-Date Fair Value [Roll Forward]
Nonvested, beginning balance (in dollars per share)												$ 0	$ 0
Granted (in dollars per share)												$ 20.90	$ 0
Vested during period (in dollars per share)												$ 0	$ 0
Forfeited (in dollars per share)												$ 0	$ 0
Nonvested, ending balance (in dollars per share)												$ 20.90	$ 0