Goodwill and Other Intangible Assets
 3 Months Ended
Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Other Intangible Assets
Goodwill and Other Intangible Assets

Goodwill is reviewed for impairment annually or more frequently if impairment indicators arise. The Company allocates goodwill to both the PBM and HCIT segments. There were no impairments of goodwill during the three months ended March 31, 2014 and 2013.

The changes in the carrying amounts of goodwill by reportable segment for the three months ended March 31, 2014 are as follows (in thousands):
 
PBM
 
HCIT
 
Total
Balance at December 31, 2013
$
4,700,610

 
$
19,665

 
$
4,720,275

Measurement period adjustments (a)
254

 
—

 
254

Working capital adjustment (b)
2,026

 
—

 
2,026

Acquisitions
—

 
—

 
—

Balance at March 31, 2014
$
4,702,890

 
$
19,665

 
$
4,722,555



(a)
Represents adjustments to the fair value of assets acquired and liabilities assumed for recent acquisitions during the measurement period. The measurement period adjustments were not recast to the 2013 consolidated financial statements as they were not deemed material.

(b)
Represents adjustments to purchase price for the Restat acquisition, including settlement of working capital adjustment.
Definite-lived intangible assets are amortized over the useful lives of the related assets. The components of intangible assets were as follows (in thousands):
 
March 31, 2014
 
December 31, 2013
 
Gross Carrying Amount
 
 Accumulated Amortization
 
Net
 
Gross Carrying Amount
 
 Accumulated Amortization
 
Net
Customer relationships
$
1,527,722

 
$
408,984

 
$
1,118,738

 
$
1,528,475

 
$
355,737

 
$
1,172,738

Non-compete agreements
11,920

 
5,594

 
6,326

 
13,430

 
6,463

 
6,967

Other intangible assets
3,060

 
1,691

 
1,369

 
3,060

 
1,346

 
1,714

Total
$
1,542,702

 
$
416,269

 
$
1,126,433

 
$
1,544,965

 
$
363,546

 
$
1,181,419



Total amortization associated with intangible assets at March 31, 2014 is estimated to be $158.2 million for the remainder of 2014, $194.0 million in 2015, $166.7 million in 2016, $147.5 million in 2017, $137.2 million in 2018, $126.8 million in 2019 and $195.9 million in total for years after 2019.